I took the plunge and got all the dependencies together and compiled Bitcoin myself to try to get the new hashing in place.  It's odd that you say that a MSVC build decreases the hashing performance, as I've found it increases it.  I'm using Visual Studio 2008 Standard on a 32bit dual core machine, so maybe that has something to do with it.  I went from ~1000khash/sec with the build from the Bitcoin website, to ~1350khash/sec by just compiling the source with Visual Studio 2008, to ~15000khash/sec with Visual Studio 2008 using the PolarSSL hashing functions.