Potato

"Interesting" is a bit of an understatement as far as I'm concerned.

But then again, I thought that we were going to find out that Humans won the Time Wars and destroyed Gallifrey. I thought that would be so cool for the Doctor to be defending the civilization that wiped his people out. So, what do I know?

I'm not sure that you can say that the Doctor ever actually messed with time. It could be argued that he was prevnting the changes to the time lines. A thought on why we havn't seen these creatures before. They are filling the void left by the destruction of Gallifrey. Without the Time Lords to monitor and police time these creatures have taken on the job. Plus the Doctor never really messed with his own history as Rose does in this episode.