Didn't like it.
I honestly preferred the older Meet the Team videos. They feel more personal. My favourite is Meet the Engineer. Not taking that into account, though, I still didn't like it. I'm seriously never playing Pyro again, because the idea of someone so delusional that they think they're spreading joy and colour when they're actually spreading destruction and gruesome death REALLY scares me. If the Pyro were just a sociopath that just liked killing things, I could deal with it. But this frightens me. I think it was supposed to be funny, but I can't see it.
I would have liked it if they had focused more on the other classes' reactions to the Pyro in the interview thing like they did with the Scout, Heavy and Spy and then interspersed (less gruesome!) action shots of the Pyro. Like the way the did for Meet the Sniper where they had those interview-style sections ("Snipin's a good job, mate.") and the action sections (giant explosion).
The Pyro vision in the game itself is funny, though. The game itself isn't as dark as the real-world parts of Meet the Pyro and the "Pyro World" isn't as bright in-game. There's less of a contrast and I know that I am spreading death and destruction, rather than sunshine and friendship.