Underlying goal/purpose of having contests
To me, the idea of having contests in the arena of DIY is a tad odd. One of the biggest reasons I like to make things and do my own projects is that it is purely creative, and it is not in the least bit competitive. We all get to put in our two cents and help each other out and grow our collective knowledge. No matter how you spin it, for every 3 winners in a contest there are still dozens (hundreds) of losers. Of course, that's not saying that the losers have bad projects, but they still lost. Game over.
One possible reason to have contests is to prompt more Instructables to be made in a certain category. Thus we have Burning Questions. But who says that the best "how to add" Instructable is submitted during the contest. The "best" one during the competition will win, but that's entirely relative to the competition. Now we have a WINNER "how to add" Instructable, which looks quite a bit more appealing to click on than any other similar submission, even if the others contain little snippets of awesomeness here and there that are above and beyond what is in the "winner." Now you have failed to capture and direct people to the best source of help on "how to add."
There are many other reasons not to have competitions, but I'll leave it at this for now so that I don't write a book.
Instead, why don't we try "Challenges" that have no deadline. Instructables can challenge the Instructables community to do projects in a certain category (just like contests) to push their agenda (reusing bottles, answering common questions, etc.). If you leave the "vote" feature active, you can then see them ranked by user preference, while never closing the field to new submissions.
Let's get some friendly debate going! woo.