I don't think Facebook truly understands the state of their service. Today's youth simply forego's Facebook in favor of Instagram, Vine, Snapchat, etc. Otherwise you've got the middle aged folks who play the Facebook games, and everyone else is just there as an only means of communication with at least one person they don't want to lose contact with. The Facebook phone thing would such a disaster.
If a Facebook phone ends up looking like an Android phone, then I don't see the point of that, really. I would rather they spruce up their native apps a little more, as they haven't even accomplished that yet. Keep it simple, Facebook and don't bite more than what you can chew.
Its funny reading this old thread, I actually ONLY use Facebook to sync my games like Candy Crush, Pet Rescue, etc. that can be synced with Facebook. Other than that I don't actually bother reading or staying connected. For me the social aspect is covered by the forums I am on.
I think Facebook for companies as advanced IM communication platform might be their first priority. A Facebook phone might be something in regions where FB wants people to be connected and where the connections are slower. I canít remember but I think there was an article on WSJ about it a few days ago.