No, Derren Brown is a mentalist. He is either capable of psychologically manipulating people, or he's a fraud. For instance, there's a video of him doing an apparent cold reading on a woman, and the woman agrees that he's right. One explanation presented on LW was that he actually made a bunch of obviously true statements, and swapped out the audio to make it seem like the woman was agreeing with a non-trivial cold reading. Swapping out audio is not a "magic trick", it's just plain fraud.
I'm fairly certain he is a fraud by your definition then. Magician's often do these kind of things, and Derren Brown is a magician. He does not have access to secret powers others know not of, so for each trick think how someone else would replicate it. If you can't think of an honest way, then it's probably a trick.
That's not to say some of his tricks aren't done by known mental manipulation tricks (as far as I'm aware, hypnotists are reasonably genuine?) but if he is doing something that seems completely confounding, I am quite happy to guarantee that i...
Todays xkcd
I guess there'll be a fair bit of traffic coming from people looking it up?