This
post seems pretty clear. Well, the first two words at least
The rest suggests you can't be sub-HD on PS3, when that's clearly not the case.
With regards the motion blur on PS3, it's there in cut-scenes but there is absolutely no motion blur that I can see on the character of Lara in-game, whereas it's abundantely obvious that it's there on 360 even when viewing the character from a long way off. I can't say that it's a major issue for me.
I think Crystal Dynamics deserve kudos for 'going for it' on PS3. It's a game where the assets really do benefit from the additional resolution, even if frame rate (and thus response from the controls) can suffer at any given point.