how can you have natural and juiced categories you going to take peoples words for it.
keep it simple one category best physique wins
The pro judges make that call. Judges like Priest, Ray, etc will be able to pick out who is using. Plus, since high quality images will be required of the contestants, that will help too.
I think most people will not cheat, because if they are caught trying to go natty and they're not, they won't be eligible for the 'Untested' category prizes. With hundreds of dollars in cash and prizes for top 3, and close to that for top 8, getting DQ'ed would suck.