I can't post this in any developper-related forum (still a noob here :p) but for those interested in cross-compiling bitcoin windows binaries from your linux box, it appears that the new "TerraCoin" thing (i felt on that bitcoin fork, by wasting time on github this morning) published a highly detailed procedure today (
http://www.terracoin.org/ ).
makefile.linux-mingw was apparently slightly altered, but other files (excepting src/leveldb/port/port_win.cc which they also altered) looks quite identical to bitcoin current files.
I think i'll give a try to the whole thing tonight or in the next days, so i can give a try to that leveldb thing
[just wanted to share the info, it looks like many bitcoin users get troubles compiling windows bitcoin clients]