Although I have the "Early" 2009 mini, I believe they're close enough.
I have a dual system installed. Mac OS X Mountain Lion and Windows 7 64 bit. I have 8GB of RAM.
You should be aware though that Apple does not officially support the 64 bit version of Windows 7 on this machine, although it seems to be working for the most part using Boot Camp 4.0 drivers.
My only complaint is about the nForce Ethernet Driver. There seems to be some problem with it. Whenever the nVidia Control Panel for video is launched, there is an error reported:
The ethernet itself appears to be working fine using some driver dated back to 2010. While I can go to nVidia's website and locate an updated driver for the GeForce 9400 GPU, I cannot seem to find one for the nForce Ethernet. Honestly, I am not even interested in the Network Control panel, but I get another error when I try to uninstall it.
Would be nice is this could be fixed. Windows 7 32 bit didn't have this issue but I want to run the 64 bit version so I can see all of my RAM.