I love this topic, I'm surprised I never looked sooner! I didn't really have the will-power to read every suggestion, so forgive me if any are repeats.
Speed up for Win8, Win7 and Vista! Let anim8or take full advantage of the processing power and RAM offered by more powerful systems!
folders implementation: group objects, figures, seqs and scenes in seperate folders.
Use attributes and ART rendering alongside bump, alpha, and transmaps to create more complex textures
simplify the accessibility and use of the 'edge properties' dialog
Easier setting of multiple views
custom colour schemes or custom skins (or an updated GUI more reminiscent of Adobe Premiere, Maya, etc commercial programs)
Sequence and scene modes- face/line stress level, green-yellow-red (maybe down to purple) lines or faces that show the level of influence a bone or morph is having on the faces or lines of a mesh. Might be useful for some people, but certainly not priority.
.png import
Audio import (even if it's basic, like mp3-limited)
Hide points and faces gets a +1 here, I ALWAYS have needed that!
Thanks so much Steve for being back and listening to the community. Being a really powerful tool with plenty of strengths and weaknesses, I really would love to see anim8or catch back up in the game!