Bullet 2.71 Physics SDK has been
released.
Walt Disney Studios contributed their in-house Dynamica Maya Plugin for Bullet physics simulation. This Dynamica plugin has been used for their 3D animated movie
Bolt. Furthermore some initial work on integrating a btCudaBroadphase has been introduced, to accelerate Bullet performance using
CUDA on NVidia GPUs. So expect some more performance increases in upcoming releases.

Download the compiled releases
here.