Some assorted interesting sounding tech:
Thrust is a STL-like tech for CUDA programming. Could be interesting, certainly looks like it is easier to use than CUDA, but just from my feelings it probably won't be worth anything until nVidia let multiple CUDA functions execute in parallel..
5 optimization tips for CUDA, a nice succinct roundup of some good performance tips for CUDA, including Arithmetic Instruction optimization.
DANCE framework for Dynamic Animation and Control, definately something I want to check out for potential synergy with the Physics engine Abstraction Layer. Proper animation controllers is something PAL lacks.
ReactPhysics3d a new open source physics engine, very much in the early stages of development, I've seen a number of engines grow in time, I hope this one succeeds too, but it will need to find a niche if it is to survive..
Predictive-Corrective Incompressible SPH is a paper on estimating the SPH state without explicitly evaluating it, thereby saving some CPU cycles. I actually had a similar idea, so maybe this is a path for further research. Also on the SPH front, Co-rotated SPH for Deformable Solids, the idea is great, not convinced by their particular implementation though..
Perhaps these ideas might make it into the SPH routines for PAL..
and on the lighter side;
2D boy's prototyping framework for the world of goo.