Another thing that I just remembered, which backs up the idea that there is some degree of choice when a timelord regenerates; the Master is supposed to have always regenerated to look the same as he 'liked' that look he had going on (I can't remember in which story that was mentioned but I'll do some digging for you.)
I know the Doctor has always left his regenerations to pot luck but evidence exists that timelords have a degree of control over the final outcome, or 'look.'
Edited to add: On reflection, It's possible that the idea that the Master continually regenerated to look the same was introduced in one of the novels which was published after the series was originally cancelled, and as such is not necessarily considered part of the 'canon.'
However, the fact that the timelords could assign a look and the fact that Romana tried out a variety of looks before finally settling on the form of Princess Astra does suggest that timelords can control the outcome of the process if they choose to.
Last edited by DenWatts : 29-05-2006 at 14:48