As I'm sure Insomniac will deliver on the technical side with Resistance 2, I hope they focus on the gameplay and try to push that as much as they can by not just adding new, exotic weapons, but rather via some brave game design.
Now this is probably the last game that makes sense to mention in this Resistance thread, but Super Mario Galaxy shows right from the very beginning an incredible amount of cool new ideas, things to do, details to take note of, an NONE of these are wiimote related. The execution comes via the wiimote of course, but the ideas per se are perfectly adoptable whatever the control method. I'm seriously impressed by everthing in this game. How everthing matters on a gameplay level. Nothing is just there for nothing. Those bouncing spherical green alien plants, for example, are just genius and joyful to play with. Anyway...
I know Insomniac (as well as Mark Cerny) keep Nintendo (and Miyamoto) productions in hi regard as Spyro and R&C series kinda followed the steps of Mario 64 better than any other game of the same genre, so I hope they apply a bit of that Nintendo-thinking to their new Resistance IP as well, even if most of the inspiration the industry has to offer in the genre is anything but Nintendo branded (well, with the exception of Metroid Prime).
In any case, whatever they do with Resistance 2 I know I'll be pleased anyway. Just try to be innovative behind the weapons.