As of October 22, 2009 Autodesk has not tested any versions of Map 3D on Windows 7, which doesn't mean it won't work, just that it's not recommended or supported.
Since Windows 7 is now the likely default OS offered on any new hardware for Autodesk products, surely some of you are giving this combination a try. If so, we'd all appreciate hearing about your experience here - please let us know by posting a comment below. Thanks!