Most, if not all, of the big players of longarm quilting machines will be there, as well as a mid-/short- arm makers are well.
And you can play on all the machines. Do as much research as you can before you go so you're not dazzled by the (very able) salespeople. ;-)
Here's the vendor list:
http://www.americanquilter.com/shows...ndors/list.php
Enjoy the show!