As far as I know, this question has not been answered by Bethesda. So, my post is really a request to them!
Just in case it hasn't been directly requested, I am just hoping to point out to the powers that be that there is huge demand in the mod community for adding custom animations. So, any tools they can throw down to help implement animations (for example export plugins for 3DS and a way to load them directly into the CK) would be greatly appreciated by many people.
Without official tools, people will most likely come up with workarounds to make it happen. But, the workflows that result from those patched together solutions typically include a lot of extra steps and limitations. That's frustrating when everyone knows that tools exist somewhere already that allow much more direct publishing and implementation.
Anyway, I hope it can be considered. Thank you for the amazing game!