EDIT: So, why do you all think this tournament is using D/P rather than PBR, which would allow for level scaling, sleep clause, etc.? Could it be that even Nintendo is not immune to the Wii shortage? Are they just trying to save money? The latter certainly seems to be the case, what with only two qualifying rounds of 128 people each.
Its probably to encourage people to use "strong" pokemon, not just random crap they caught then put on their teams. I'd prefer the open level thing anyways, it just feels more in the spirit of the game as lame/queer/lol as that sounds. Its probably for the better anyways, since it allows for strategies involving lower leveled Pokemon.
The other reason may have just been that they, for whatever reason, wanted to hold a DP wireless tourney as opposed to PBR. It reflects the battle tower better that way, and they'll probably just input the standard double cup rules for the tourney.
PBR for the final round really throws things off imo. If I recall correctly you get to view your opponents team no matter what before the battle in PBR. If you're using 4 man teams already, your entire strategy could be revealed. Hopefully they'd either let you bring 6 to the finals (which in my opinion would effect the way I build a team) or they set it up for you before you go on the big screen, which is what they'll assumingly be using.
I really wish they'd let me participate though, I would save up for a trip to NYC. I assume it just has to do with the way things are taxed in canada vs US, but the tourney is already international anyways.