I still don't buy that Lord President Bond (love that!) was THE Rassilon. First off, the guy has been dead for how many thousands of years? And when he appeared in the Five Doctors, he looked like the Ghost of Christmas Past, a right jolly old Timelord.. He wasn't a dick. I can see it if somewhere along the line, Lord Presidents took the monikor of "Rassilon" like the Roman Ceasars of old...
Well, from the point of view of simple logic, there is no reason why he can't be that Rassilon. Do we really believe the Time Lords would resurrect a criminal like the Master without bothering with their founding father?
Also, The Writer's Tale confirms that he is supposed to be that Rassilon, with RTD indicating he would have brought back the same actor from The Five Doctors if he were still alive.
Finally, I have heard some people state while Rassilon's depiction in The End of Time is the first time he's been actually evil, the audio dramas which have featured him over the years have made it clear he was never an angel.