I feel it is my duty to contain my thoughts here, hopefully to prevent them from spilling over into too many other places.
This is the one I have heard the least about, so I'll start here. Rumors include a change in name to the Orbis (still going to type PS4 for now,) which is apparently (or so say nerds on the internet) Latin for Circle thus creating a little pun when paired with the Vita (Latin for Life) of the Circle of Life. Is it just me, or is this insulting to us gamers to imply that our lives begin and end with video games? Don't get me wrong, I play way more video games than your average person, but even I admit that video games are only a small part of my life.
Next rumor is around the elimination of used/rental/borrowed games by locking a disc to a console. These include an ID for each game that is only valid once for a game, any other system would have to pay Sony for the right to play the full game on their system. Depending on price, both of games and this renewal, this could break Sony, and officially kill off the Playstation line. If it's not too much (between $1 and $4), it may actually fly, especially if they drop the cost of new games back to $50 or less for new games. This $60 garbage for new games is one of the reasons I didn't personally shell out the money for a PS3 or 360. Personally, it is offensive to actually pay for a game and know I don't have full access until I pay again! Sounds to me like paying for a demo. Call me crazy but demo's should be free since it's really just an interactive advertisement for the full product.
Controls better change significantly. The Dual-Shock 3, the primary controller of the PS3 is simply an upgraded Dual-Shock from the PS1. So after over 15 years, we get wireless and some tilting hardly anone uses? I want to see some changes in the controls. That design has been done to death! This would be the equivalent of the NES, SNES, and N64 all being released with the same 8 directions, 2 action buttons, with a start and select button controller. Controllers need to grow, and Sony has been stagnent for too long. I would bet on more Move like controls, but I just hope they get rid of the stupid colored orb on the end. Then again with the name Orbis, perhaps they plan to keep as many orbs as they can.
The connectivity of the PS3 and Vita is only a mear foreshadowing of what we should be expecting from the PS4. This actually ties back to my last point about controllers. If they don't go for the Move style controls, Vita may be the new controller. Based on the potential of the Wii U, this may actually be an option as well. Perhaps a stripped down Vita could be the controller. The Vita's could be used in place of the controllers. The "normal" controllers could have the same functionality, but wouldn't be stand alone handheld systems like the Vita. Especially if Sony plans to go in the same direction as Nintendo is, this may be an option.
One of Sony's big advantages of the previous 2 generations of consoles was in the accessibility of programing for their systems. This current generation, more than a few times, developers have lamented over the difficulty of programing for. I would argue that may have cost the PS3 some things. They still seem to have a better 3rd party relationship than Nintendo, but it has started souring. If Sony wants to contend in the next generation, they better work harder to keep their 3rd party support. That sense of entitlement is what slowly but surly brought down the monolith that was Nintendo to where they are today. In all fairness, the low point for Nintendo 3rd party wise was during the N64 days. But it's along hard climb back once you lose that 3rd party support, as Nintendo has been learning for the past decade.
3D 1080p is one of the buzz words around Sony right now. I'm not going to dispute the option, I am going to argue that it won't be accepted by the majority of consumers right now. With a huge influx of LOUSY 3D movies assaulting both our eyes and our wallets, I am beginning to think that 3D entertainment may have to wait another 5+ years. Hopefully by then we can all wash the awfulness of Avatar and the like off and give 3D another shot. The poor release of the 3DS is a good indicator that 3D just isn't ready for prime time gaming yet either. It sounds cool and all, it just doesn't seem to be good enough to warent the extra cost yet.
One of the rumors that may also give Sony a harder time launching the PS4 with success is the lack of backward compatibility. While I agree that the cost and size restrictions placed on a new system to ensure backward compatibility does exist, there are an overwhelming number of benefits. First, when a system launches, it's gaming library is quite pitiful. While sweet launch titles can help with that, and systems are launching with more and more games each generation (remember when 3 games for a launch was amazing,) it still is nice to be able to extend the games you can play right away.
Particularly if the owner hadn't owned the prior console, this can give them an option to play a lot of really great games. If they offered downloadable versions of previous generations games, it can be a great option for those who never owned them, but for those who still do own them, it's offensive to have to pay again for a game you already have! I even read recently someone arguing that backward compatibility doesn't work well when it is implemented. While I agree the examples he used (PS3 and 360) have some issues with backward compatibility to a point that it's not worth using or mentioning, there are plenty of great examples of it working and well! The PS2 was actually the best at this since it actually made load times of PS1 games go faster. The DS line launched with compatibility for the GBA line, which itself had compatibility with GB and GBC. The Wii has backward compatibility with the GC, and having that compatibility actually opened the door to some games using the GC controls as an additional option for Wii games.
Now it would be nice to be able to keep every system, but who has the room to do that? Especially with a fatty like the PS3, that thing takes up more room than my Wii, PS2, and DVD player combined! Also TVs limit how many inputs they can have, forcing us to make choices of what we plug in. And of course, you can't forget the fact that systems do break down eventually. If a system breaks, you have to replace it, repair it, or just chuck it. But if the next system has backward compatibility, then you can finish any of those games you were playing before the system broke down. And while I would never do sell my system, some people trade in their old systems to be able to afford the new systems. Without backward compatibility, it's harder to justify that. Personally, I like to leave my old systems to friends and loved ones who don't have a system of their own. There are always those less fortunate than yourself. Unless you are a dirt farmer in some third world country, then it doesn't get much worse from there.
While nerds are going to argue how much better processing that Sony and Microsoft are going to cram into these beastly machines, the only way wer are going to see significant changes is if they go Solid State for the components. It's going to be expensive, but that is the angle Sony took with the last generation, and I don't see them focusing on anything else. I just hope they don't Neo-Geo themselves out of the market. Granted since Sony has huge penetration of the market already, it's not likely that it will be as hard to find a PS4 as a Neo-Geo was, but that price tag sure kept my teenage-self from picking one up.
The other problem with going for so much power, is that by the time you have released it, the technology is already outdated. PC's will always be better than any console, and since you can change various components of your PC, truly hardcore gamers who are looking for that edge will always gravitate towards the PC. Now there are those who claim that the controls are what set consoles apart from the PC, but with the ability to use how many different types of joysticks now, I don't think that argument really has any weight left to it. PC's are just expensive to keep up to date, and what may be good enough one year to play a game, may be too outdated to run the sequel next year. Consols just keep a standard for a period of time. Previous generations have run in cycles of around 5 years each. This has been an exceptionally long system cycle, and Sony may try to make the next one last even longer.
This leads into my next thought, which is release. I doubt we are going to hear too much about a solid release date till after the Wii U actually launches, and Sony can really see what they are going to be competing with. Nintendo is in the weakest position due to the aging Wii, Sony and Microsoft just need to keep enough rumors going about their next consols to keep the Wii U from getting too much of a head start in sales. Depending on how powerful the Wii U really is, within about a year, we will see the PS4 and next X-Box released. Support for the PS3 is going to fade inversely as fast as PS4's are sold. If the PS4 takes off, then PS3 will be lucky to get another year of support. If it has the same assimilation problems the PS3 had, expect the PS3 to have more than a 10 year life span.
Since nothing is set in stone till Sony releases it, the PS4 has tons of opportunity to change to fit the market, but if they continue down the path that some rumors point to, it may be a system that only Music/Movie Stars, CEO's, and Wall Street Bankers can afford to buy. If that be the case, I'm sure it will look pretty, but it won't be hooked to my T.V.