By the way, I discovered there are desktop version of the mobile build available for developers (Windows, Mac and Linux)
http://ftp.mozilla.org/pub/mozilla.org/mobile/releases/4.0/
Windows http://ftp.mozilla.org/pub/mozilla.org/mobile/releases/4.0/w...
Mac http://ftp.mozilla.org/pub/mozilla.org/mobile/releases/4.0/m...
Linux http://ftp.mozilla.org/pub/mozilla.org/mobile/releases/4.0/l...