I was there in May '03. I noticed no difference, but my mother did say that she got the overall impresion that things were slipping. But I also go to Six Flags a lot, and Disney on it's worst day is a million times cleaner!
I think it has a lot to do with the manners of the guests. Many guests are just not considerate of other people and the CM's!!! How hard is it to put something in the trash? Why do people need to pile heaps of tp on the bathroom floor? (I never could figure how or why that happens!)
It also could depend on when you go. Rehab work is done over the winter, so if you go in the fall it will look worse than in the spring, because they haven't had a chance to do a lot of work yet.
I'm sure the staff cut backs and overall decline of Disney has something to do with it too. But I'd rather put up with with a bit of rubbed off paint and some dim bulbs than risk Disney going belly up. Just look at this whole Comcast thing!
In any event, even if the parks really aren't kept as they used to be, they're still the best run theme parks on the planet.