Better graphics (which really isn't just higher resolution), better physics, better multi-tasking which opens up new features/combinations of features (in-game browser, cross game chat for PS/Wii U). It increases excitement among consumers, and I imagine it's the same for developers... if you've been working on the same machines for 8 years I'm sure things can get a little dry for some. New, more capable platforms spark enthusiasm. New generations bring general change, so it just keeps things fresh.
And this is only stuff I know will likely happen, I'm really looking forward to the unexpected things as well.








