You all have to remember that Android 2.1 is not out yet either. I'm sure that the Motorola droid will get 2.1 pretty soon after it is formally released. In the mean time HTC is working on the 2.1 sense upgrade which will most likely come well after Android 2.1 is formally released. HTC will have to QA their software against the released android which will take some time. Since the 2.1 Sense UI has already been leaked for the Hero I would guess they are not even bothering with 2.0. There is a lot broken in that build for the hero currently so it'd definitely not ready for prime time.
Motorola Droid is a true Google phone and should get 2.1 not long after Google releases it. HTC has work to do to qualify so it could be a bit after 2.1 is released before we see it.
That's my guess anyway on what's going to happen