Wizard's first rule comes to mind, but honestly, I kinda liked some of his ideas. I found it enjoyable to watch the same way I find it interesting to read threads on these forums about ideas everyone has that they think Diablo 3 should adapt from other games or completely new ideas.
Even if you somehow didn't catch the fact that he is playing the gameplay video and not the actual game, there are plenty of clues that he is just messing with people. One is the fact that he said there are 10 classes, when it very clearly states in the Blizzard FAQ that there are only going to be 5 classes. His ideas are not even believable, it is extremely obvious that he is just messing around.
Of course most of you have figured that out by now, but I just felt like posting
No joke. He has good reason to though. Poor guy has cancer, hes a really nice guy if you watch his videos, and Blizzard has given him a beta. Check it out, he even mentions a third class that he has access to, (though doesn't discuss it).