I tried SpikeWAMP today on a virtual image (VMWare) of Windows Server 2008 RC0 and it worked fine.
Windows Server 2008 RC1 (which is the latest one out there) seems to have some problem with Cygwin. The stack installation got stuck for a long time - I traced it to a python process during the configuration phase of the stack. The process just sat there eating up all my CPU. Eventually, I had to kill it manually using Task Manager.
When I tried installing vanilla Cygwin, the installation also got stuck during the postinstall phase. Basically any bash or python process seems to get stuck indefinitely. My post on Cygwin mailing list revealed that other people are having the same issue with RC1.
Hopefully, this is a bug that will get resolved in upcoming RC releases of Windows Server 2008.