So who's writing it?
Good odds on Tony Lee.
He's denied writing it in the Bleeding Cool forum.
However, I suspect that this is related to the "big" Doctor Who
project he's mentioned several times on Twitter, especially around the time that it was announced that he was leaving the ongoing monthly.
By the way, if no one's noticed, according to the February PREVIEWS
, Doctor Who
#16 is the last issue of the ongoing. I suspect that this crossover will be taking its place. Hopefully, when it's done, we'll get another ongoing Doctor Who