For web servers, especially those which are acting as load balancers and SSL terminators, let alone if deep packet inspection is involved, hooking GPU will probably accelerate performance dramatically.
I managed to find few projects[1] and papers out there, and it would interesting to see others or take active part in such project, indeed.
[1] http://http.developer.nvidia.com/GPUGems3/gpugems3_ch36.html