Curious if there are new animation tools this time around, or is this just a huge rendering engine upgrade?

Couple things I would hope to see are onion-skinning for better alignment, and rotation alignment that works with the align tool in the right click menu of the timeline. Hopefully it would use the avatar's chosen alignment bone and orient it to the alignment (rotation) of the same bone in the previous clip. It would need to be the temporary top of the IK chain for this to work, I guess.