I think that should be about right. Brilliant games take lots of time to develop and plan. If we see the engine advance as much as we did with Ratchet & Clank (far more SPE usage combined with texture streaming) Resistance 2 should technically become mind blowing from the technical perspective!
I am impressed by R&C with regard to polish and draw distance. It's really cool flying around a level and seeing the dinosaurs down below and in the distance. 8-)