Welcome back Bobby! The actor who portrays Bobby, Jim Beaver, tweeted "Try not to get too excited, but I'm coming back to SUPERNATURAL. For real." Oh and be warned... spoilers...
I don't know about you, but I am getting pretty damn excited about this. If you remember, last we saw of Bobby was when Sam ventured into Hell to save Bobby's soul from eternal damnation. He ascended to heaven but with the recent events of season 8's finale, it seems the whole balance of Heaven has turned itself upside down and [SPOILERS] all the angels of heaven have fallen to earth and lose their ties to their heavenly powers. Could this mean that Bobby had become an angel and he himself had fallen with the rest? Knowing SPN, I wouldn't be surprised if they thought up something that we as fans would never think of.
Either way, it's good to see Uncle Bobby back. Since his "death" I really missed Jim Beaver on the show.