Thoughts on Turn Left (some of which have already been posted on TWOP forums, so if they look familiar, that's why):
It's heartbreaking to me that, left to his own devices, the Doctor would have essentially killed himself after Rose up and went to alt!verse...but moody destructo-Doctor is kind of hot. In a totally genocidal way, of course. (Note: why is it okay for him to destroy entire species but not okay for people to shoot each other? I'm just asking.)
Oh Donna, poor Donna. So does this mean Donna's going to die? I get that the alt!Donna needed to die in order to reset the timeline, but Rose's reaction suggested more than that. As did River Song's closed-mouth unease at hearing Donna's full name. (And yes, I get the fact that River exists on a point in the Doctor's timeline which is relatively far in the future...but she wasn't all "Oh, yeah, old companions, whatev," she gave Donna a look that was more in line with "I can't tell you because wow, what a way to go. And also, you might want to reconsider life insurance.")
Is regeneration a willful thing? Does a Timelord have to do anything to make it happen? Make a funny face, do a little dance? The alt!Doctor's death coupled with the Master's non-regeneration suggests that's the case, but I'm not familiar with anything beyond the last three (and three-quarters) series so maybe it's been explained already. Of course, that would mean that Jenny's magical mystical regeneration/interpersonal terraforming makes even less sense than ever...
Rose. Rose Rose Rose. I loves me some Rose, and would have loved her more had she not been doing something terrible with her mouth. Alt!verse is apparently hard on the diction. And the hair. (Note: but how cute was she when she got all bubbly about the Doctor's hair? Died, that's what I did.) Also, I really hope she changes clothes at some point. But in any event, it's lovely to have her back for the next few eps, and I am desperately hoping that she doesn't get crushed by a piece of falling masonry or something.