Yes, that’s The One Doctor and Christopher Biggins is Banto Zane, that imposter. The STARDIS was the teleport they’ve faked up to appear like… a portaloo (the “dematerialisation” sound effects being one of the funniest of the many gags).

Evidence for:

The simlarity of the title “The [One/Next] Doctor”

The original was essentially a BF Christmas Panto, this will be a Christmas Special

Banto-like pomp & overdone costume

Fake looking Cyberman equivalent to the Skelloid non-threat

Evidence against:

Gareth Roberts is not co-writing even though he is collaborating on one of the specials.

If I’m right I hope it’s not too similar to The One Doctor because he will struggle to better it… Though I doubt they could realise the shelves of infinity on TV! “Enough talk of this foolish Earth pan!”

Come to think of it, I guess RTD has borrowed from it before, since Bad Wolf was not the first time The Weakest Link had been used in Doctor Who…

With regard to alternative universes, I thought (but can’t find the quote, so maybe I imagined it) that RTD said there aren’t alternate Time Lords…