PLEASE READ: No doubt many people, like me, have been speculating what will happen when The Eleventh Doctor and The Master finally meet. Now, nothing I've come up with is particularly complicated or profound, but what I've written here is a basic summary of what I think Eleven himself would think of The Master.
The Doctor (Eleven) speaking to The Master (most likely EoT version or a very newly regenerated version, as yet unseen)
...there used to be a man, didn't there? A man who believed that everybody was worth the risk it took to save them. A man who could look at you and see, where all others saw evil and insanity and, and, and sheer bloody mindedness, a fellow Time Lord, broken but savable, with the potential to become something brilliant, something beautiful.
But then he changed.
And he looks at you now, standing before him, and d'you know what he sees? He sees a monster, something as alien to him as you are to the rest of the universe. He sees this and he knows, really knows for the first time...you're not worth saving.
Yes, that's what I think would happen if Eleven met The Master. My reasoning is this- Ten was much more idealistic than Eleven, and allowed his own emotions to rule much of what he did. Eleven won't allow himself that luxury- if there is something out there that he perceives as a threat, he'll get rid of it, and The Master definitely falls into that catagory. Cries of outraged disagreement to the usual address please. Or maybe you agree with me, who knows? Whichever, please review and let me know :)