I'm usually all *turn off brain* for movies and TV shows (it's too distracting otherwise!), but I read a couple of spoiler-free reviews before seeing Inception and was thus prepared to turn on my thinky-thoughts just this once. ;)

The ending seemed too easy to be real (and I'm glad that it wasn't resolved, one way or the other), but maybe the point is that it doesn't matter as long as Cobb perceives it as real.