Like Rob, the thing that really struck me about this episode was how very dark it was, but again, as he said, it's not the first time that RTD has done dark - and he's always done it very, very well. He really does go by the philosophy that with kids it's only gore (along with sex and swearing of course) that's off the table. Kill off the Doctor, kill off Sarah Jane, kill off the kids from Sarah Jane Adventures, kill off the Torchwood team. Kill 'em all.
The wartime-esque scenes in (gasp) Leeds were wonderfully bleak too - it's amazing that a line as simple as "It's happening again" could have me and mum both reaching for the tissues, but the fact is that RTD can make us care deeply about characters in a matter of minutes. We were genuinely sad to see the man who had let Donna's family and so many others into his home taken away to such an abhorrent fate, and yet we knew next to nothing about him - we didn't need to, because what RTD had told us was more than enough to know that his death would be a tragedy and a disgrace.
As for Rose's return, I won't be the billionth person to mention her bizarre speaking style, and instead say that this wasn't really her story, it was Donna's, and it was very creepy. Rose will only be back in earnest when she's face to face with the Doctor or Jack - she has no relationship with Donna, other than recognising how important she is, but with those there is history and emotion. It was telling that we only really saw the old Rose, the one who isn't quite so cold, when she was talking about the Doctor's hair...
Overall, a brilliant episode that was as much straight drama as it was sci-fi (so often the best) , and a brilliant taster of things to come, you imagine. Here's a question though: since when did Bad Wolf mean the end of the universe? It was a good thing in the first series, wasn't it...? I clearly need something explaining... :P