Mr. Chalker, could you please clarify what "official decision" needs to be made? Isn't it as simple as taking the states with the highest registration numbers until the full complement of 60 teams for each division is reached?
Yes, it is that 'simple'. What isn't simple is that the registration numbers aren't finalized yet. Keep in mind that while some states have already had their State tournaments, in other states the regional tournaments are just getting underway (for example in Ohio our state tournament isn't until late April).
Technically you can register right before a regional and still compete (although I doubt few teams actually do that). While most of you on this message board have been working on SO stuff for months, a significant percentage of teams don't seriously start until a few weeks before the tournament.
Thus the national office sets a deadline of April 1 for locking in the numbers. There might be a few additional registrations that filter in after that date, but in general most everybody has registered by then.