David Tennant's 39 or 40 now, actually. Yeah, the thing with him is that he's cute, young, fit, but with old, wise eyes.
Sadron, I have to comment on your perplexing misunderstanding: "Rose" is the very first episode of the new series of Doctor Who, and it starred Christopher Eccleston as The Doctor. He was absolutely amazing as well, I hope we're not forgetting.
Here's the thing, guys. Remember the end of season one? You LOVED Eccleston, I bet (I did.) He was a god to me. (I'd not watched the original series, so my first taste of Doctor Who was with him.) And then he vanishes, replaced by this pretty new fellow!
Like Rose, we were a little wary. Right? RIGHT? Admit it. In those last twenty seconds of The Parting of the Ways, you hated the bastard who dared kick Eccleston out.
I think some people were thinking that they would never like the show again, never watch it again, The Doctor's not supposed to be so pretty, he doesn't know what he's doing . . .
Matt Smith will surprise us. Have faith.
(For the record, I do think Smith is rather easy on the eyes as well. He has quite the frightening chin (but when you're The Doctor, it's easy to overlook things like that and crush on him anyway, *cough*Eccleston'sCrazyEars*cough*), but nice eyes. He's so FRESH. The actual character, the Doctor that Tennant was playing, was tired and disillusioned and heartbroken and afraid and in the end, a wee bit selfish, even cowardly (when it came to the matter of his own death, which was understandable and added to the depth of the character)
Smith's Doctor is young and naive and untouched by all the crappy aspects of The Doctor's existence.
I think it's a beautiful thing.
They haven't cast a terrible Doctor yet, have they? (Not that I'd know, really)
Plus, Steven Moffat, you guys! Freaking STEVEN MOFFAT. The guy behind The empty Child, Blink, and The Girl in the Fireplace. Those are three of my favourites!
Okay. I'm rambling now. In summary, please don't stop watching, please give the poor lad a chance.