NVIDIA Releases Beta PhysX Drivers
Whether or not you believe that (read their response here), for end users, the real question is: "where are the drivers? I want to try them." NVIDIA has posted beta versions of 177.39 on its site. Just remember, they're beta, so the normal warnings apply.
Windows Vista 32-bit
Windows Vista 64-bit
Windows XP 32-bit
Windows XP 64-bit