Animator Pat Smith has a great post on "The Firebird" segment from Disney's Fantasia 2000 which I recommend to you :
Ted Kierscey's Animation of "The Firebird"
Very inspirational . We need to see this sort of thing to be reminded of what 2D animation is capable of and how really we only have just scratched the surface . Be sure to check out the progression clip that he posts from the Fantasia 2000 DVD :
Firebird Progression Reel