Yah, i know, but the difference is Nexus One was a Google product.
Hero or Dream are HTC products as Motorola with Droid, but in these cases Google didn't take the main role.
I don't know why this has changed in Nexus.
As far as I can tell HTC is making the Nexus One. Google doesn't do hardware, unless I missed that point.
In any case, Google, HTC and Motorola seem to have some branding issues. One is called the Passion on one network, and called the Bravo on another network, etc.