Yup. Today is a huge day for Windows Phone indeed and, to top it off, the official Facebook app just hit 2.0 and finally (finally!) brings Push Notifications (Toast + Live Tile) to the game.
What's really great is just how much you can choose to be notified on: Message, Wall Post, Feed comment, Feed comment reply, Photo tag, Photo comment, Tagged photo comment, Photo comment reply...etc, etc. All of those are optional for notifications, which gives you the user some great control over how the app works.
Overall, the app feels smooth and now, dare we say, is complete? Go get it here in the Marketplace. (Thanks, @wp7ap, for the heads up!)