The same EXACT thing happened to me, and I took it in to the verizon store. They replaced the phone, and it still didn't vibrate. An hour or so later, the new droid started vibrating. The tech there didn't know what is going on, and I sure as heck don't know what is going on. But if I were you, i'd try to start safe mode, if it doesn't vibrate in safe mode, take it in. If they can't fix it at the verizon store, they will replace it and hopefully after a little bit your new droid will work fine like mine.
If it works in safe mode, it is most likely related to a third party app that you have downloaded. Safe mode only opens the stock apps on the Droid, so that is a good place to start before wiping it clean.
so i was starting it in the "safe mode" and it would do the droid animation and then show the eye..then go black for a few seconds and then restart the droid animation and so on.. is that normal?
I have this same issue. I figured it was a bug with Android and didn't think much of it since I rarely use the vibrate function. I haven't tested it since the 2.0.1 update, but if most people are saying it's fine for them, it makes me worry a bit. If you end up doing a hard reset, please post results.