[buildmaster5000]

If we are going to throw around location ideas, the DC Convention Center has at least 4 halls, each one with more than enough space to support a 65 team regional. The issue would come, I think, when you have to put 4 or 5 sets of bleachers up at once. And I believe DC has airport hubs for United, US Air, and Delta.

In all honesty, the space we had for the first 2 years of the DC regional could have squeezed close to an entire second regional into, so my guess is that someone, with a lot of planning and measuring, could get 6 regional sized setups in there no problem. But somehow I don't think space is FIRST's biggest concern with the championships...