Turck MMCache development is on hold (for indefinately), but as it was released under GPL the development has continued under a different name(s). One of these new versions (forks in geek speak) is called eAccelerator. It's still in early stages so I wouldn't try it on a production server, but they have released Windows binaries that you could try out. More information at
http://sourceforge.net/projects/eaccelerator/ and the Windows binaries (DLLs) are at http://www.arnot.info/eaccelerator/.