A very credible inside source (VZW engineer) actually confirmed this on Twitter today. He said HTC doesn't upgrade Sense on older devices, and it sounds right, because I can't think of a single phone where they've done that. And if anyone is to be believed, it's him
I would love it if Sense was updated as well. I think most of us are in agreement that the DInc will get Gingerbread at some point. But I tried to register on HTCSense.com and they only support the Desire Z and the Desire HD in North America (so far).
HTC and Verizon were pretty good about getting 2.2 out, and I thought I read somewhere that most HTC phones were going to get the new Sense UI. Maybe they're just waiting for Gingerbread to come out first?