EDIT: watched the conference and it just made me sad. technical progress for the longest time has meant more explosions and polygons, when you could use the additional tech to up framerates & resolutions or just have more complex stuff going on all at once. now additional horsepower will be squandered away on useless shit like recording your gameplay to post on facebook when all modern games play the same every time anyway and nothing you record will be unique in any shape or form anway. *sigh*
also: the infamous guy tells it like it is how surveillance is scary and oppresive, when minutes before they've told us we'll get a camera monitoring us and psn is gonna learn you spending habits, and using anything but your full IRL name is discouraged now.
They've been saying for a long time that graphical leaps will get narrower and narrower with every generation. It doesn't surprise me one bit that the jump isn't significant. One very small thing that I am excited about is basic PC architecture. Like the original Xbox, this should make it VERY easy for developers to squeeze a lot more out of the PS4 than they would had Sony gone 100% proprietary as they've always done in the past.
Don't know if you recall the PS optimization software that Sony
eventually released to 3rd party developers near the end of the PS1 lifespan, but it really opened the doors to things that nobody thought was possible with the hardware. That's what Sony used when developing Gran Turismo, which was a technical masterpiece at the time. Was nearly moot though, since the PS2 was right around the corner. And speaking of, I'm sure we've all heard the stories about how difficult it was to program for the PS2

This step towards PC-based hardware, while not nearly as "cool" as the super custom chipsets and whatnot, is a good move IMO. I'm sure Sony has taken a cue from Microsoft, who's machine is seemingly able to keep up with the PS3 on almost all fronts, despite being a good deal older with weaker hardware. May open the door to a lot more indie devs too, which means more retro-like games, which makes me happy

No Backward Compatible 
Why is this an issue for people like us? I hear so many "hardcore" gamers bitch about that all the time. Who cares? You've got a PS3, so what does it matter if the next console isn't BC?

Not to mention the headache that is moving save files, re-downloading content, etc.