I honestly don't understand the anger towards Russell T. Davies based on the Doctor/Rose ending and the Donna ending. I just don't. Based on the logistics of what he had to work with -- the Who universe itself, Billie Piper done, Catherine Tate signing on for only one season/series -- I thought he did everything he could. He gave the Doctor/Rose shippers the ONLY possible outcome for a happy ending with Piper leaving the show. Could it have been made more clear that the blue suit Doctor was still the Doctor in that final scene? Yeah, but the overall intent was definitely there. And the final moments where it was revealed completely that the Time Lord Doctor just could not emotionally give himself to Rose no matter how much he loved her (in keeping with the long-term theme of the show), while the Time Lord/Human hybrid Doctor could showed that this was the only way that Rose and Doctor COULD have that kind of happy ending.
Yes, it could have been executed better; yes, we could have had a scene or two showing that blue!suit Doctor was still the Doctor, especially with Rose. And yes, there were things that were off and not presented as well as could be in the final beach scene. But RTD's idea behind it all was pretty amazing that he even went there.
As for Donna, Catherine Tate signed on for only one go. That was it. The only option that Rusty had was killing off Donna, and I know I wouldn't have wanted that at all. This way, Donna still lives. Did she lose the memory of the last two years? Yes. But will she stay the same Donna from The Runaway Bride that she would have been had she not met the Doctor? I don't think so for a second. It was a small scene but telling when the Doctor called Sylvia on how she treats Donna. Sylvia may have been pissed, but she'll remember it. And Wilf may have loved Donna before and believed in her, but now he's seen the absolute proof of what she can accomplish. So with their attitudes different towards her, a confidence and belief in absolutely everything and anything that she can be, she'll become that same brilliant Donna we came to love. And much faster too. Because the memory may be gone, but that self-confidence, the events that shaped her are still there written in her DNA.
Russell T. Davies gave both the Doctor and Rose, and Donna the only possible non-death, happy outcome that he could possibly give them within the confines of the structure of the show and the logistics of the actors not staying beyond this season/series. Because a Rose who didn't die would NEVER have willingly left the Doctor ... unless, she had the Doctor (albeit, with a few changes, incidentally ones that will allow him to be with her fully in every way). And a Donna who didn't die would NEVER have willingly left the Doctor ... unless the memory of all that she had experienced with him had been erased. But again, the experience is still there in her heart and soul, those who love her the most around her will encourage her in a way like never before, and will have a faith and belief in her like never before. She WILL become that brilliant, fantastic woman that we all fell in love with in no time.
THAT is what Russell T. Davies gave us even within the logistics of actors' schedules and the structure of a long-running television show. And that was on top of a pretty damn good finale that kicked all kinds of ass, used a lot of Who history and brought together a lot of what we loved about the show. So even with my few quibbles about the finale, to him I say BRAVO!!