Agreed, out of the relaunch series David Tennant and Catherine Tate were and awesome team; for me Tate was the best companion for the Doctor, because she truly is a best friend. And I loved the silent window chat in the beginning of their season, just hilarious.
And I agree with you Laeren, there is a lot of separation from the past doctors except for the snippets of flashbacks. I have a feeling this is itself a relaunch from the relaunch; there is a definite feel that the new writers are separating themselves from Russell T Davies' work. That's probably their intention, but they don't want to completely pull themselves away from the mythos of Doctor Who.
As for theories... that's a tough one. I wonder if it has anything to do with River Song having murdered an important man?...
The episodes are online, floating somewhere on unofficial channels... just gotta do a little searching for them. ;)