Early builds appear ahead of official update
A Windows Phone Tango build has reportedly surfaced ahead of the formal update, which will be relabeled 7.5 Refresh when it arrives. Unofficial developers quickly jumped on the leak, crafting unofficial ROMs for HTC's HD2 and Samsung's Omnia 7 handsets.
Most functions left intact, sans Marketplace
Owners of HTC's HD2 handset appear to have yet another OS option, as members of a group called DarkForces Team have reportedly refined a hack that enables the device to run Windows Phone 7. The custom ROM is said to provide most of the basic WP7 functions, but with a different mapping for the buttons below the touchscreen.