Given how the BBC seems to run things, Series 6 will air its first episode in March of 2014, then we'll have two more episodes, then nothing until Christmas, then in 2017 the other half of series 6 will air. During this time we'll have 5 new companions.
I haven't seen the BBC handling Doctor Who that way. I assume you know the story behind the 2009 specials (if not, buy The Writer's Tale and you'll see Davies and Tennant had it planned before the Tenth Doctor took his blue suit in for its first dry-clean). Series 5 is on schedule. There's no indication of a mid-season split (may still happen but I think we'd have heard by now). Season 6 is in the pipe. Sarah Jane is supposed to go into production soon if it's not already. BBC America is running the show, almost immediately after the BBC UK, Space in Canada will probably follow suit.
The only unknowns are when Torchwood is coming back to BBC and if there's going to be a Christmas special for DW. I don't see there being a problem. And if the BBC has commissioned a series 6 then it's showing confidence in Matt Smith (for an example of what happens when the BBC does not have confidence in a new Doctor, see Colin Baker). We're in good shape.
Yes. They are going even younger and selecting 20 year old Daniel Radcliffe.
Don't laugh. Apparently he was one of the people whose name was buzzing about. I don't know if he was ever seriously considered, though. Not just from his age, but the fact the guy's going to be known as Harry Potter forever. They had enough trouble getting Davison to be seen as the Doctor and not the guy he played in All Creatures Great and Small.
Mind you, better than Russell Tovey (Alonso Frame from Voyage of the Dead). For whatever reason RTD had it in his head (at least in Writers Tale) that Tovey would make a good Doctor (in part because RTD unambiguously had a crush on the guy). Tovey was great in VOTD, and I hear he does a great job in Being Human. But he looks too much like a 13-year-old to be a convincing Doctor. There is such a thing as too damn young for the part; Smith looks young too but at the same time he looks like a guy in his 20s. Both Radcliffe and Tovey still look like teenagers.
As for McGann appearing, I don't see it happening. It's too much of a fanw*nk. I mean, OK a 7-minute cameo by Davison for charity is one thing. But an entire episode devoted to a Doctor whose one and only TV appearance occurred before a huge segment of DW's viewers were born, and in a film that is a complete unknown factor (thanks to the lawyers) to most North American viewers. I just can't see it.
I think the only way we're going to get a regeneration story is for Big Finish to do an audio of it. We know the BBC is not opposed to another party doing the regeneration -- Doctor Who Magazine was all set to regenerate the Eighth Doctor and had even had the scene drawn, but they couldn't follow through because the BBC wouldn't allow the Ninth Doctor to travel with anyone other than Rose and DWM wanted to use its ongoing companion Destrii for a Year One story arc (the BBC evidently loosened up with Ten as both DWM and IDW have been allowed to create new ongoing companions for him).
Part of me though likes the fact we don't know what happened to Eight. It adds to the mystery surrounding the gap between the movie and Rose, and I've always liked the fact we learned a little bit here and there (most recently in End of Time) regarding what the Doctor did during the Time War. To spell it all out would spoil it, I think. And there's certainly no shortage of audio dramas featuring him, and since they're licensed by the BBC, and a number of them are even broadcast on BBC Radio, I consider them to be just as legitimate as any of the TV stories. There just aren't any pretty pictures to go with them.
Alex