When Den of Geek asked if fans should expect him to appear as the Doctor in the special he answered:
“No! Somebody mentioned something that the BBC is running on the weekend when it goes out. Big Finish have done us proud, they’re coming out with something really exciting. The BBC, we’ve heard nothing though.”
Two actors that have played the Doctor, David Tennant and Matt Smith, have been confirmed by the BBC for the special so far.
The special will air in November this year.
[Sources: Digital Spy and Den of Geek]