That's what we originally thought, there was an article published confirming it even. But Steven Moffat specifically denied it and said that because of scheduling conflicts Benedict Cumberbatch would not play The Master. I was very disappointed.
I think Cumberbatch would make a great Doctor. Although I think if he ever was, he'd have to be Gingerbatch! >:3 Although hasn't he already said he doesn't want to do it, as he's already in Sherlock. Although I read rumours of him being the Master for the 50th Anniversary; if that ever happend that'd be awesome too!
Great art by the way, nice style. You've captured his cute little face well ^^