Nerd,I thought Bilbo looked so much older at Rivendale because he's no longer being kept young by the ring, not because a lot of time has passed. "A lot" being relative, of course -- they don't tell you how much time in the movie, but I get the impression Mr. Jackson wasn't trying to make 17 years pass.
A lot of people are complaining about bits and pieces, but did anyone really not like it at all?