I'm not totally in love with the brighter graphics, but yesterday I looked at the article about how people had photoshopped released images to make them a lot darker and more detailed. I can understand (after reading the article) that the lighting cannot be done. The developers stated that there was no way to make the light's AI (for lack of a better term) work in that realistic a way. In all fairness though, if they DID manage to do that so that it was just incredibly dark all around your character bar about 3 inches of light around you, I'd end up just turning up the game's brightness level until I could actually see what the hell I'm fighting anyway.
I'd like to see the atmosphere darkened a little, particularly when inside a dungeon, but I think the developers were right about the outside areas. They don't necessarily HAVE to be all gloom and rain. Fine, make it raining... but that doesn't mean the sun cannot be out too. Hell, seeing how that rainbow that caused so much controversy was above a waterfall (even if it was upside down), I think it made sense. You're supposed to be pretty high up at that point, so even the claim that it would be impossible to see it from that angle is wrong anyway.