I attended last year and it was a bit of fun, a good laugh, and plenty of other stuff to do because it is on at the same time and venue as the Royal Canberra Show! Bring the kids, etc!
If you want to see whats going on at the Royal Show then check here:
http://www.rncas.org.au/showwebsite/main.html
If you're interested in coming along for the ute show, here is the schedule and entry form:
http://www.rncas.org.au/showwebsite/06utesched.pdf
http://www.rncas.org.au/showwebsite/06uteentryform.pdf
It does start very early in the morning, but overnight stayers are welcome. I have plenty of floor space for campers.

Cost to enter is $25, but that includes two entry passes to the Royal Show as well, so thats not bad value.