Bullet 3.x will feature a 100% GPU accelerated rigid body pipeline with various parallel broad phase algorithms, convex and concave triangle mesh and several parallel solvers. Here is a teaser video for my GPU rigid body talk at GDC 2013 this Thursday March 28, 2.30PM. See some Youtube video here.

See http://schedule2013.gdconf.com/session-id/822773 for more details.