Yes, I am posting this to the right place - for under this cut lies the theory that Mr Saxon is, in fact, one Irving Braxiatel. Contains spoilers for S3 [Human Nature & Family of Blood] and the alleged casting spoiler regarding John Simm.
Now edited to include
doyle_sb4's rather fabulous nugget of information from the comments.
According to The Sun, John Simm is playing The Master in the S3 finale. Apparently said spoiler came either directly from him or from one of his colleagues. If it's true, it would be the first time a major plot point from a New Skool finale has been leaked in advance, apart from Billie's leaving (which the BBC denied through a good chunk of S2). Even then the only textual hints about Rose's departure were that she would die in battle, which didn't happen. My guess is that it's been deliberately leaked, either because it's a red herring or because there's going to be a big twist. He's supposed to be disguised (or, based on the last two episodes, have taken human form?) as Mr Saxon, the new Prime Minister, and it's been rumoured that he and the Doctor are brothers.
Now for proof of my theory: Braxiatel is a consummate politician, and according to some sources he's the Doctor's brother. Um. That's it.
The only flaw in my theory is that he isn't technically canon. It's a pretty big flaw.
Romana's presidency is possibly canon, since it was alluded to in an article in the 2005 (I think) Doctor Who annual writted by RTD himself. Obviously this doesn't automatically make everything in the Gallifrey audios canon, but the Braxiatel collection is referred to in The City of Death. And Human Nature novel was reworked as an episode, which could maybe pave the way for an audio character to be introduced into the series without relying on the audience being familiar with the Big Finish work.
doyle_sb42 says that the Radio Times breakdown of the season does (inexplicably) feature the sentence "who built the Ark?" And as we know from Gallifrey season 3, Brax did...
And according to his wikipedia entry:
In the Tenth Doctor television story Smith and Jones, the Doctor mentions that he once had a brother, although he gives no details which could identify this brother as Braxiatel. However, the script editor for this episode, Simon Winstone, also edited the novel Tears of the Oracle in which the brotherly connection (between the Doctor & Braxiatel) was first made.
In conclusion - Brax is a tricky bugger. I wouldn't put it past him.
Obviously I'm not 100% serious. But it would be awesome and people should write fic. *nods*