"Photo real" is definitely the prime category, when we talk about Terragen. You can make pretty photo real images with the free version, you just have to choose a scene that is not so much affected by the free version limitations. For example, don't create a scene that relies on a big variety in populations.
The contest theme will allow for that kind of flexibility.
Frankly, TG2 is all about photo real, so that category is a must.
In all honesty, we don't want to limit the scope of the contest based on free or not free edition. We just want to honor the best image, whatever it takes.
About the voting system, we still have to figure that out in detail. Our initial thought is to allow one vote per category, which makes it simple. Most likely a normal survey could provide that functionality. Once we decide to let people vote, there is always a possibility of cheating, which we will surely attempt to prevent, but there is no guarantee of success - that's a risk we would take. After all, this is for FUN and not something really serious.
We think the benefit of letting everyone participate in the outcome outweighs the cheating risk. It sure would be an experiment, as we have never done that before.
In the end, IF there are serious problems that we can't overcome with a public voting, we can still resort back to a jury model.
I think this is all probably secondary, as the actual act of contesting in creativity and skill should be the primary motivator for participating. The past NWDA contests have created some of the top community experiences on these forums in the past. That's what counts! :-)
Cheers,
Frank