If you look here:
http://icehousegames.org/wiki/index.php?title=IGDC#Previous_Winners
...you'll see the following ratios:
Summer 2007 - 37 judges, 8 games (first IGDC in almost two years; a strong argument for going annual only; though a lot of the votes came from one class of kids, IIRC)
Winter 2008 - 15 judges, 8 games
Summer 2008 - 10 judges, 10 games
Spring 2009 - 12 judges, 5 games
I am of the opinion that judging is orthogonal to (a) design and (b) feedback. More promotion would provide more judges, though; and it would also bring more eyes onto Icehouse in general (hopefully). Last year's IGDC--for all its low numbers--had some really good feedback, as I recall; and it also resulted in two of the more-fun games on the wiki (IMO).
That said... I have been looking at how Game Chef is going this year and am thinking what we might learn from Graham's experiment:
http://gamechef.wordpress.com/
it's VERY feedback- and collaboration-oriented, with group assignments. It also isn't locked to a "end" date--one can get "badges" for completing a game at any number of time stages, up to a year (I don't like this notion for IGDC, by the way). And it's very, VERY much about finishing a game, not "winning," like Nanowrimo. I think we might want to re-evaluate the IGDC after this next one in 2010 (earliest it's likely to be complete, it being November already).
Also, folks, keep in mind that we'd be in the Tenth IGDC--sort of a milestone, ya?
...And the 2011 IGDC would coincide with the Twentieth Anniversary of Icehouse!
Goo timing all around, for a larger change than design-restricted or not (or voting method).