Oh, huh. I assumed it was not registered since Blender uses "™" instead of "®" at the top of its homepage. I guess that's just for the logo then, not the wordmark.
Amusingly, you don't have to use either for it to be a registered trademark, it just makes it "more obvious". It also makes word marks look like corporate capitalist nonsense, so leaving it off does all of us a service =D
