Here's a bit offtopic answer but that's the solution that I use. There are many implementations of Alt+mouse window moving trick for MS Windows. Choose the one that you like (or write one more, AutoIt/AutoHotKey are waiting for you) and enjoy X11-like user experience.
Hm, after that I have an idea: it would be nice to have such option in XMing/vcxsrv (if they don't have one yet).