The technology field is highly competitive not only in the products launched but in employees. Competitors are always after key workers at places like Apple, Intel, NVIDIA, and AMD. Workers routinely move from one company to the other as they are lured away to the competition.
NVIDIA has reportedly lost its VP of CUDA and PhysX Manju Hegde to AMD. Hedge was key in helping NVIDI Again support for PhysX and CUDA early in the life of both offerings. Both are doing well today.
The loss of Hegde certainly won't spell doom for NVIDIA, but AMD should reap some benefits. AMD has been unsuccessful for the most part in getting the developer community to adopt its platforms like HDR with AA. Hedge should be able to help AMD a lot there.