David Hayward has an excellent article about non-photorealistic ways to design videogames and the effect this might have on game mechanics and depth. Something that translates very well to machinima and the wish for better engines and more polys...
from the article:
Technological development does not solely equate to the development of photo-realism. While the aesthetic development of games will to some extent occur in conjunction with improved technology, and while the corporate games industry will continue the photo-real push, what's already been done shows that utilisation of newer hardware is by no means the only boundary to be pushed.
Go read it here.