This is a topic I have been going back and forth on for a while.
1. I love the idea of an allstar team because it would make Science Olympiad even more like a Major League sport.
2. I also love the idea of an allstar team because the best of the best should be represented at the national tournament. No offense to anybody, but some teams compete at nationals that wouldn't place top 10 in a state like OH, PA, or NY. Thus, the national competition is really like, and I truly believe this, 1/2 as hard as it could be if better teams were chosen from really competative states, or if individuals could qualify for nationals.
3. On the other hand, Science Olympiad is about being a team. You can't qualify as an individual for the NBA finals, you need your team with you, and in that sense, Science Olympiad does the right thing by not having individuals qualify.
4. There is absolutely no way to get the best people to the national competition because it is too hard to judge the best people. A state champion in a very weak state may not place top 20 at a state with really really competative teams (again, like OH, PA, or NY). The fact is that not all teams are equal, and thus it is impossible to judge people against an always differing standard.
THE BOTTOM LINE: I would rather see 3 TEAMS go from the best states (instead of just 2) than sending individuals to the national tournament. For example, Mentor, from OH, placed 5th at nationals in 2007, and didn't even get to go back in 2008. Who knows what they would have gotten considering they were the third place team at the OH state competition in 2008, and the LOWEST OH team at nationals (as in highest placing, as the OH teams at nationals placed 2nd and 3rd) placed 3rd in 2008. This would not only make 15 people happy (instead of just individuals at a time), but would also garraunteee a more competative national competition for everybody.