McGann makes half his living from voiceover/audio work so I'm guessing that with Destiny Of The Doctor just about over AudioGo are getting back to original 11th Doctor audiobooks and he's reading one. Probably this one.
Another returning companion. http://www.doctorwhotv.co.uk/another-companion-returning-for-50th-53741.htm Maybe?
How would they get around the rather big issue concerning Spoiler: plot point from last time her head burning up if she remembers? More of what we saw in The End of Time?
Spoiler: Speculation It could be some kind of journey into the mind/through the timestream that makes her appear. I have a feeling that some of the Classic Doctors are going to cameo this way.
Spoiler: Speculation It could also simply be Donna before she became The DoctorDonna or she may only see HurtDoctor and SmithDoctor, but, not TennantDoctor, so, no reason for her to remember anything, or we might just get a cameo of her home life in the background or.....
Spoiler: spoilers I could see something like Hurt's Doctor discovering Donna during the time war and hoping to make use of her knowledge and unique human qualities to help the war but in violation of all kinds of temporal rules. I can see the timelords having the ability to forestall or stop her dying as they having medical resources that the Doctor alone in the Tardis didn't, or he goes ahead anyway and Donna is good with it, she didn't want to go back after all. It would add a whole new level of guilt to later Doctors as they'd know what was going to happen to Donna all along. I can see that being something they might like to disown.
Those are both possibilities. I think the first is more likely but the second is quite a bit more interesting.
I think it would fit with how Moffat has handled other companion paradoxes. He handled River's story with the Doctor knowing all along when and how she would die after the Library. He was going to take on Victorian Clara when he realized she was the one on the Dalek Asylum and later found Clara for similar reasons. I can see him doing something like that with another companion.
Likely nothing, sure, but there's little else to talk about. Surprising given how close we are to all this.
One month? It's only the 10th. It's a month and a half out, but, yea, trailer ought to be coming soon.
Donna? Seriously, I like the character, but it really ought to be someone from the classic series. This devotion to the new series is getting a bit too much now.