Spent a week at Burning man in 2012. I'll put my pics up here soon.
My three sentence review:
Burning man clearly used to be something else, but now it is The Worldwide Street Art and DJ Convention.
Only enough freedom remains to allow the tiniest bit of punk culture to poke through here and there, and if you are very unlucky you may see less punk and giving than you will see law enforcement and stupidity.
Sadly, the new art may be in knowing how to have fun at this bloated festival - it's like a zen koan - if you are at once prepared and clueless, giving and stingy, observant and careful, cautious and totally batshit crazy - you will have a lot of fun and stay out of trouble.