We are working on making MPD compatible with mingw32. We migrate a lot of stuff from POSIX APIs to GLib.
Cross compiling from a unix environment Edit
mpdclient-win32-env is a build environment specifically for MPD clients and now supports building MPD itself. The purpose of this environment is to make building of MPD related programs easy for when release tarballs are needed. The environment will build all dependencies when feasible; this is so a good debug package can be guaranteed. Only win32 is supported now, hope to support win64 in the future.
It will never be released and will always be in git form: http://git.musicpd.org/cgit/avuton/mpdclient-win32-env.git/