Firstly, to get an overall impression of what to expect, Youtube as always has a great video, titled "Burning Seed 2010" - of Australia's first Burning Man event. From arriving, to the partying, fire, and more, it gives a solid 12 minute taste. The only problem is in answering your question with the video - much of the footage is at night, and it's not always easy to tell whether people are clothed as they're often just silhouettes!
Then there's the trailer for 2011's Burning Man in Australia. This runs for about 3 minutes, and including the climactic final scene around the fire, there is no sign of nudity - despite being a trailer, I'd have thought it hard to hide AND include that final scene.
However, one of the founding and guiding principles of the event is radical self-expression, so it certainly seems from that, that nudity would be tolerated or even embraced. Probably find it just takes one, and others will follow...
The website for the Australia Burning Man event.