It's not absolutely confirmed, but one of the show's directors let slip that the "plan" is to have the show start in July of this year - slightly before the August/September timeline that was being quoted before.

I still feel really nervous about this, because I want it to be good, but Moffat threatens, as always, to Moffat it up.

Also Matt Smith said something kind of questionable about Alex Kingston's potential return as River:

"I'm really possessive over Alex [Kingston]. I said this to Steven [Moffat]. I was like, 'Listen, just don't! Just not Alex. Anyone else, but don't give [Capaldi] River,'" says Matt Smith during a Q&A panel at the New Orleans Comic Con.

"But Peter is the Doctor now so hey, what can I do? But I am really proud of the fact that Alex was part of number Eleven's life. My wife!"