I ask because I have been migrating more and more code into scripted languages and over the course of several discussions have come to realize that I am likely still under-utilizing scripts.
I think it's important to ask yourself what your priorities are. Scripting languages have a number of issues of which performance is only one, especially when combined with other languages due to debugging and interface barriers. For this reason many of my colleagues and friends in the games industry have been moving away from scripts to trying to use data driven systems and graphical interfaces (such as Unreal Kismet / Crytek Flowgraph etc.) for designer editing of behaviours.
A high performance physic system seems an ideal space for using a compiled language like C or C++ with all the tools available, and low level capabilities such as intrinsic access to SIMD arithmetic and efficient multi-threading. If you're looking for an easier way to program SIMD then you may want to look at ISPC.