The Day of the Doctor includes one more Doctor..we thought David. Matt and John would be the only doctors..wrong. Former Doctor Tom Baker has revealed he IS in the 50th anniversary episode, The Day of The Doctor.I am in the special," Tom, who plays the fourth Doctor Who told The Huffington Post. "I’m not supposed to tell you that, but I tell you that very willingly and specifically; the BBC told me not to tell anybody but I’m telling you straightaway.”
Baker then said working alongside more recent incarnations of the Doctor was a pleasant experience.
“It worked out very well, I think, judging by the reactions of the technicians,” he said.
So..what role to you guys think Tom will play..my guess is he will be the doctor but that might not end up being true..from what Tom said it looks like he will have quite a big role..i hope it's not just a cameo
http://www.mirror.co.uk/tv/tv-news/doctor-who-tom-baker-reveals-2812767