I really loved the last 5 minutes or so with the conversation the doctor and Adelaide had. It really shows you how close the doctor really could have been and could be to becoming like the master. (thinking the rules of time are solely his to command, etc.) And of course the following realization when Adelaide shoots herself afterward. good snap back into reality, in a horrifying sort of way.
And I don't think he's running specifically anywhere at that end, just away. He'll probably just be called, in a way, back to Donna/the master/etc.
This episode has really made it hit home for me that he's really going to be going. ;_;