Processor: They should stay with the cell architecture, by the time this generation ends, devs will have spent enough time and learned many ways to program it efficiently. Switching to anything new and forcing devs to learn to program for a new architecture would be catastrophic. Just give the cell some more juice and horsepower....and more ram.
VideoCard: Graphics card will be improved, hopefully enough for 1080p to be the new standard while pushing graphics more toward photo realistic visions. More memory on the video card would be nice.
Media format: BluRay would obviously stay since Sony put so much money into it, but the read time has to be much much faster than it is right now.
Controller: Controller would probably be some kind of transforming wii-mote/traditional remote.
Ram: I want 4gigs or more just like my PC, but that's not going to happen. Anyways, I think the memory is the most important improvement to be made. There needs to be more ram since 256x2/512mb puts too many limitations even on some current games.
HDD: Maybe 250gb standard laptop HDD for all PS4s?
Online: PSN.... but with a free membership option (which allows you to play for free) and priced membership option (more options, and features). Hopefully PS owners will have in-game XMB, Home and KZ2 by the time the PS4 arives.. *HOPEFULLY*
Price: $350 on launch. If they stay with something close to what i posted, it shouldn't be a problem. Bluray will be cheap by then and so will Cell. Ofcourse, it could depend on the economy.
EDIT: and i would also like some acustic dampening foam inside the PS4 to reduce noise. and for those wondering... ther WON'T be a HDMI cord in the PS4 either, since most of you already bought one for the PS3 :P
