I expect to be implementing this myself, but anyone may feel free to beat me to the punch.

Mongos.exe runs on windows, but is not configured to installitself and run as a service. This renders production use impractical on windows.

util\ntservice.cpp is pretty generalized so only some minor tweaking there and some refactoring to move functionality in db.cpp to cmdline.cpp asn will allow this to happen.

Justin