I officially switched to 64bit last night, and finished re-installing all of my apps this morning.

I'm very happy to report that the bump in performances is definitely noticeable.  Under my 32bit setup, the camera movement in the Preview window with the Pose, Hand, and Face cams was a slide show, so I just used Fast Tracking to move around.  Under my new 64bit install, camera movement is smoother.  I don't know how to measure it, but it looked like I was averaging about 15fps while navigating my scene.  I can't wait to add another 4GB of RAM.

:D