Do Timelords Have Some Form of Control Over Their Regenerations?

When a Timelord regenerates there might be some influence on their part as to what form their next regeneration will take.  Let's look at this with the regenerations we've seen since the show's revival.

When 9th Doctor, Christopher Eccleston, regenerated into 10th Doctor, Davis Tennant, he was in love with Rose Tyler and perhaps wanted to be younger like her.  The next regeneration we see is the Master, who states, "If the Doctor can be young and strong then so can I" before regenerating into John Simm, who was younger and stronger than his Professor Yana persona.  We then witness the 10th Doctor's regeneration into 11th Doctor Matt Smith, at this point the Doctor feels old and weary and wonders if he has lived too long.  He regenerates into a younger, more carefree version of himself.

The Doctor comments that he could look like anything, have three heads or no arms perhaps, but yet every time we see any Timelord, they always look human.  Perhaps the Doctor will finally get his chance to be ginger.