It does make me worry though; a phone exclusively tied/forced to only one social network is a scary idea.
Yeah, I agree but have you tried an android phone? Pretty much requires that you sign up for a Google account to maximize its functionality...
True - as does iOS I suppose. The reason I worry is because (I would assume) a facebook phone would have no apps for other social networks, because facebook, for obvious reasons, want to keep the user entirely based on their network.