First of all, Matt Smith is great and you'll love him, Keith. But it WILL take a few minutes of the first episode for you to shake off the "that's not MY Doctor!" syndrome that plagues us all after every regeneration. Do try to shake it off - I know people who stubbornly haven't and have missed out on enjoying a lot of good stuff this season.
Second of all...I didn't like the 10th Doctor's end. I believe it was realistic, and fit very will with how far the character had fallen since Donna left him, and how far into selfishness he had gone. But to me, his reaction to his death didn't match the heroic nature of the man who would, without thinking, sacrifice his life to save Donna's grandfather (who's name escapes me right now).
RTD always seemed to have this obsession with writing the Doctor as this, as he put it, "lonely god" character who could never really be happy. I didn't like that. Moffett, on the other hand, has always written him as a man who will go out of his way without question to save EVERYONE.
"Everyone lives, Rose! Everyone lives!" vs "I don't want to go."