The ONLY reason I even bring that up is b/c I saw a user on here just a few days ago who evidently had his gmail account hacked, and Google shut it down. They eventually restored it, but it sounded like he had a heck of a time getting it restored.
When you first activate the Droid (or any Android phone), you have to log into a Google account. So, in his situation, he could've just started a new Google account to get in and use the phone's functionality... but, all of your contacts are synced with Google, your Gmail is synced with Google (obviously, and there is a separate email client if you use something else), your Market purchases are attached to your Google account, your search history (if you so chose), Google Voice, etc... you get the point. If your Google account gets hacked or shut down for any reason, you lose a lot regardless of your phone. But if your phone is that tied to your Google account, then you can see the potential problems.
I think you can still use the phone and get around the initial activation page, but I'm not 100% on that. There are a lot of potential problems in that worst case scenario, but to me the worst would be all of the contacts that you couldn't get to.
Obviously this is an absolute worst case scenario, and I've only seen it once, but still something to keep in mind... at least in my anal mind.
It still bothers me sometimes how dependent on Google I am.