The team at xda-developers are finally getting close to a highly stable and usable version of Android for the HTC HD2. This particular installation has working WiFi and cellular data. You can also make calls, but the speaker doesn't quite work. If you've got an HTC HD2, this is easy to try and you can always get back to Windows Mobile by soft-reset. Just load the files into your storage card, run Haret.exe, and wait for a while.
Get your file here from xda-developer forum.