Weren't there already some very ready looking game titles for PS3 at the E3 conference. Sure they weren't playable yet, and might not be playable at TGS, but imo enough not to make me worry much about the state of PS3.
The state at which the PS3 and it's games are presented now and in the coming months are more a decision made based on marketing strategy and hype building than anything else I think.
Maybe Sony just has little need to push the developers to produce playable demos for TGS, but instead allows them to concentrate on E3 2006 for maximum imnpact before launch, and more polished playable code.
Sony in a tough spot, I don't see it that way.
I'm not talking about the Killzone, but the game trailers like the ones from Insominac, Ubisoft and Sega (Fifth Phantom or something like that).
While nothing awesomely jawdropping, they certainly matched the claimed gameplay videos of what MS had to show (certainly tons better than the so-this-gen-average-PC-game-looking PDZ! (IMO)) and looked next gen enough, at least the framerates were fluid and overall they looked quite polished already.