For kicks, I backed up all of my stuff and installed the 64bit version of Win7 last night, and then I installed PPro 2010.  There was only a slight, but noticeable, increase in overall performance.  After a brief experiment, I removed Poser, made an image of my 64bit install, and then recovered my 32bit setup.

It felt really nice seeing all 4GB visible in the Control Panel, too.  There's no need for me to build a new computer, or simply upgrade my CPU, but I'm definitely going to stick another 4 GB of RAM into my PC.  Newegg still has the RAM I bought - 4GB for $100 - so no problem there.

On an unrelated note, I noticed that Poser's Library is not dockable in 64bit.  In fact, the square you can click on for docking options in the 32bit version isn't even there.  It's not an issue - I usually leave it undocked in 32bit mode anyway - but I found it rather curious.