Sent an email to Bart the other day which pointed me out to this forum as well. I think you guys have been doing a tremendous job with sketchfab.
So, getting onto it, one of the things it would be tremendously great for is the implementation alongside facial motion tracking. Here's a video of facial mocap successfully imported into sketchfab but with no sound there's little use for it:
with the consumer VR just around the corner I'd say this is a key feature that's missing. I can see people jumping on the bandwagon once they see great animations with good sound design as well.