I just went through the lists of bands from the past 3 years (all that NSHS has posted on their TOC page), and found 14 bands who's calendars say they'll be attending.
Birdville, Guyer, Thomas Jefferson, Grapevine, Hebron, Frisco, Allen, Rowlett, Weatherford, & Northwest, plus the usual CFB-ISD schools, Creekview, RL Turner, Ranchview, and Newman Smith (exhibition).
Any other schools going?