I was gunna suggest some stuff... but we seem to have gone off topic... Oh well I will say it any way.
Walking animations : when You hold "C" to walk, your blockhead should walk Like the backwards walking animation, 'cept your going forward.
Server-sided faces and decals: obviously this would be an option in the "options" tab. The face and decal that the host is wearing will be downloaded to the client, And then added in to his faces & decals list, much like music. Ultimitley you would see much more of peoples avatars and also adds more custimization to new players who havnt figured out how to download add ons.