It pains me to have to say that I agree with Gizmodo's review in general, from what I've seen.
The HD2 is the best WM phone out there, there's no doubt about it. But it's being utterly crippled by WM6.5. HTC's done a fine job covering up WM's horrendous user interface, but they don't have 100% coverage. Sooner or later, you're going to find an area of the UI that HTC hasn't covered up, and you'll be subjected to the full horror of WM's archaic default interface.
It's pretty clear by now that this phone was originally destined for WM7, but was shoehorned into 6.5 after WM7 was delayed to late next year. It's a shame, because it seems as if WM7 would have been a significantly better fit for what is otherwise a stunning device.