Money quote, from Moffat himself:
"My entire career has been a Secret Plan to get this job. I applied before but I got knocked back 'cos the BBC wanted someone else. Also I was seven."
I've been a drooling fan of Moffat's since 1996, when the Who anthology Decalog 3: Consequences came out. I had a story in that volume (only my fourth published short story, in fact), and so did Moffat: "Continuity Errors," which may be the finest Who short story ever published (though Allyn Gibson's "The Spindle of Necessity" comes close). He later wrote the Comic Relief special "The Curse of the Fatal Death," which was equally brilliant.
And then he joined the cabal of writers working on the 2005 revival, and gave us "The Empty Child," "The Doctor Dances," "The Girl in the Fireplace," and "Blink," along with an upcoming two-parter, and anyone who doesn't list all or most of those episodes in a list of top ten 21st-century Who episodes should get 40 lashes with a wet noodle. He gets Who fundamentally, and knows how to make it sing.
Don't get me wrong, I'm completely pleased with the job Davies has done. But if he has to go, I don't think there's anyone more qualified to take over.