8 GB GDDR5 unified ram fully available for games, with a seperate pool now rumored for OS. The demo's shown above were running on previous dev kits with a lot less ram.
Just read that 900,000 people have signed up with Gamestop for info on when PS4 preorders are available. Lot of hype even at this state. So should be a pretty good launch for them. Every major developer is on board, the launch lineup is looking really solid, and they've removed previous limitations for independant developers. Anybody will be able to make games for this system, which is pretty neat.
Also of note, ps4 has 4K playback for movies, and Sony is launching a 4K movie service to go with it.
You'll also be able to play all PS4 games remotely, via wifi, on a Playstation Vita. You'll be able to control the entire system from the handheld, which is pretty cool. So all the above, playable on your lunch break.
I agree, the stuff looks phenomenal so far. Should be a hoot.