Paul McGann has stated that he would definately do more Doctor Who in the future should the opportunity arise to do so.
"Well, it's like with the mini-episode - if they send you the script and it's good, you'll do it," McGann told Doctor Who Online, "So, you know, these things are only as good as the material. So the real question is if the material was good enough and if you were available, you'd do it - cos it's a Who!"
McGann continued to describe the lengths he went to in order to keep his involvement in the minisode and prequel to the fiftieth special 'The Night of The Doctor' a secret. "That was tough, keeping it a secret," he declared. It wasn't easy. I mean a couple of mates knew - family knew, and I'm pretty good at keeping a secret.
"But of course so many people work on something, you know, technicians and everybody else, and publicity people, you know, I'm not pointing the finger, except I'm saying, somewhere along the line, someone couldn't resist pressing send. "A couple of days ago we were seeing still pictures from the episode going out before it had gone out [officially], so Steven Moffat presumably thought 'I've gotta do something', so we released it."
Below, you can watch Paul McGann in The Night Of The Doctor