I don’t know if any of their changes are relevant to Urho (bugfixes perhaps?), but here’s the announcement:
http://bulletphysics.org/wordpress/?p=456
Apparently it brings inverse kinematics support, which would be an excellent feature to have.
I googled bullet 2.84 IK demo and came up empty. Is there a demo?
My guess is at this point no – currently I don’t think they’ve even updated the documentation, but it looks like there might be such a component in the video they have showing 2.84 off.
The IK demo is located here.
Do we have cloth physics yet?
It’s actually 2.85. Urho already had 2.84 last time I checked.