Okay, we all knew there wasn't to be a regeneration. The whole point of the year of hiatus was to facilitate Tennant staying, after all. That said, I have definitely had enough of DOCTOR WHO seasons that end with shots of Dave Ten-inch standing at the TARDIS console, looking dis-console-ate. Oooh, I've saved the Future Earth from Daleks/Present Earth from Daleks and Cybermen/A hastily botched alternative Earth from The Master/All flamin' reality from Daleks (delete as neccessary), but I'm still all alone. Let's find some new tropes, before we all get bored. Even the kids who are still eating this stuff up, oblivious to us oldies, rolling our eyes behind them.
Other than that, fair enough. When the second-last episode of the series was so everything bar the kitchen sink, it's only fitting that the last episode is everything plus the kitchen sink. With the role of the kitchen sink being played by K-9. Good dog.