Like most others here, I just kinda shrugged my shoulders at all of this stuff. The Killzone footage, a series I quite like, really didn't look much better/different than Killzone 2 and 3. To be fair, those two games are among the best looking games on the PS3, but still. That's how I felt about everything they showed. Nothing made me think I need to go throw down hundreds of dollars for this machine in nine months.
Honestly, the best part of the conference for me was something that they did NOT show, and that was The Last Guardian. Yes, for the first time ever, I'm glad that game wasn't shown because it brings me hope that it's still a PS3 game. The Last Guardian was in the back of my mind when I purchased my PS3 four and a half years ago and while I would not feel cheated if TLG was a PS4 exclusive, I would be bummed if it never even came out for the PS3.
And while this conference left me pretty unimpressed, I know that in the end Sony has an infinitely more appealing stable of first/second party of developers than Microsoft does. That's not going to change overnight and it's going to matter more as third party exclusives, even timed exclusives, truly become a thing of the past. It's happened already. So for me, unless Microsoft really blows us all out of the water, Sony will continue to be more appealing between those two.
Good news though, EuroGamer is confirming that used games will work on PS4.