My take on the whole thing: This will just be a fun tournament. It doesn't really offer any prizes, except to the top 8 finishers in the country, so everyone else will just be S.O.L. as far as that goes. As for pride, there's really no pride in winning this tournament, since the rules are seriously gimped and not conducive to competition. There's a chance that the winner will turn out to be a really good player, but I can't see this necessarily translating into any future wins.
So I'm going to go there, and just play because I'm obsessed with Smash Bros., not because I want to win. I think there are going to be more worthwhile tournaments coming up within the next few months anyways. If you're looking for competition, just wait for some that members of Smash Boards set up. They'll be far more rewarding and less...corporate.
Or better yet, you can use the Gamestop tournament as a chance to network and set up future tournaments in your area. Tournaments where you win prizes the same day.
Anyways, just have fun. The payoff is good if you have the dedication, but to me it's just not worth the hassle, especially due to the rules.