Gutted because of the episode! Though now you mention it, gutted because it was the last one too.
I just feel so, so sad about Donna. The way she'd done so much, been the most important woman in the universe, saved the universe at least twice... and now she's back to her old, humdrum life, without knowing just how great she was/could be. How will she achieve her potential now? Chances are, she won't.
Still, as my mum pointed out, she seemed happy in her old life. Also, I guess it would be worse for her if she remembered everything but could never go back to it. But the bit where she begged the Doctor not to wipe her mind... And the bit at the end where she didn't know him and dismissed him casually as some stranger... And then where the Doctor was alone in the Tardis... *sob!*
Conversely, Rose's (second) goodbye didn't affect me in the slightest, even though I was in floods of tears when she first got separated from the Doctor. I just had no emotional attachment to her this time, and her lisping voice was really getting on my bloody wick.
On the plus side, the Doctor "regenerated" into David Tennant! Two David Tennants!! One of them briefly naked!!! (Although the camera angle was a little too high for my liking.)
I don't really understand why the Doctor is always reluctant to kill - he castigated his other self for getting rid of the Daleks, but surely it had to be done? They were going to destroy every other lifeform in all the worlds! Surely a timelord would see that it was necessary to save everything else?
Anyway, it was a good episode, but I found lots of it very sad. And now I'll have to wait until Xmas for more David Tennant. :(