Its a nice phone but I don't know if I want to jump in heads first just yet. I think the n1 will stay atleast one update ahead of the pack as a development and early test phone. And if that's true ill go for the n1 if not come on desire
And, moreover, HTC is not really known to be a company with long, extended support for older devices. Take a look at their product page: products from 2, 3 years ago do no longer receive any support.
Other thing why I want the nexus and not the desire is the fact that HTC has left out the noise cancellation and voice features. In "return" you get the hideous, unstructured Sense UI, which I don't like because it seems less intuitive and customizable than the native android UI with its clear structure.
Moreover, this proprietary UI implies that HTC will need some time to adapt new android releases and, in consequence, will not update the ROMS when a new version arrives.
I want the nexus for this: Google for now only has 1 flagship and they will want to keep their costumers satisfied. Plus, their is no extra tweaking to the UI involved, which will make faster updating possible. If the nexus would turn out to be restricted to the markets it is available to at this time, I would say: Desire: pick up stock android and come to papa!