I thought that the NACCC was recommending that the top ten in each division made finals, regardless of division size. This would insure that CEA/WC/MT were in finals even if there were only 3-4 teams. This would also effectively create an incentive for teams to even out the distribution of teams among divisions. (want to go large senior in 2011 - automatically in finals!)
This also means fewer total performances, which allows things like: more divisions in the Field House (maybe all of finals?), more warmup time, possibly more seat availability, & possibly easier/more fair judging of finals.
There would be downsides as well. If you are in a huge division, this could dramatically decrease your chances of performing the final day.
I actually don't know what came out of that recommendation - I am not in the loop on very many decisions like this about Worlds.