One physics engine not explicitly mentioned (which deserves its focus) is PhysX, recently acquired by nVidia along with their buyout of AGEIA. nVidia is already working on converting the PhysX codebase to take advantage of CUDA enabled GPUs as a replacment for the dedicated physics hardware put out by AGEIA in the past. The engine is freely available from nVidia as well for PC development, and integrated in game middleware solutions like Unreal Engine so I’m sure we’ll be seeing it used more and more in future titles.
http://www.nvidia.com/object/nvidia_physx.html
http://developer.nvidia.com/object/physx.htm
Havok was showing a demo of their engine running on GPUs as well at GDC a few years back as well, so it’s definitely headed that way.