A few days ago we broke the news about the Genuine Software checker for Windows Phone 7. To recap, the system would check the OS against the hardware using PVK (private keys)--if no match occurred, then the OS would be crippled (no cloud services).
Now DFT, the team behind the attempted Windows Phone 7-to-HD2 port, have come forward and said that indeed, this is the case. The result, as predicted, is that the OS is "mostly a demo" without the Live services but that "...it will be released soon, but don't expect anything from it - without Live services it's not really usable".
Looks like Microsoft has won this battle, for now. But it is still early in the game and perhaps someone will figure a way around the security.
Bottom line: if you were expecting a usable port to happen anytime soon for your HD2, you can stop hoping now.