It's pretty impressive. Emulating the real world Burning Man, the festival is laid out on a playa and includes a temple, themed art camps, and of course The Man. I selected a Windlight setting of my own (Barcelona) as I thought it looked better - use your own judgement. You may also want to wear only necessary attachments, leave your huds at home, and reduce your script count as the playa can be laggy due to the complexity of the installation.
BURN2 is open to Second Life residents October 1-9.
Here's a video and a few photos of what I saw today - enjoy!