to weigh in my opinion, i think we should see a solid influx in contests, before the forum is created. their is talk of multiple up-coming contests, but until things are concret, it doesn't make sense imo. also, if we only have 1 or 2 contests a year, it's really alot of wasted space imo.
Can we get a Competitions/Contests forum?
We do now have a 3d modelling contest in the Visual Arts forum.
I think it might be worth doing something -- especially if the current momentum of more regular small contests continues -- but I'd really like to look at non-forum options properly. I really think we could do something pretty cool by using tagging to collect content together from different parts of the site, and it seems to have recently worked pretty well having contests in various other forums. More official contests could create a more official page in the hypothetical new section rather than just using topics, but forum topics seem to be pretty simple and effective for the current community-driven efforts.
In any case, I think it's worth some proper thought and planning rather than just throwing up a forum to see how it goes.
Perhaps a locked forum thread in the lounge which gets updated on the first post by mods (as needed) as to current and new competitions with a link to the appropriate competition thread wherever it is located onsite.