I've been out of this competition a little too long to really comment on the overall design (although it looks very solid). Two quick things, though:
1.) I like the built-in follower wheels. Just so you know, VEX nows sells "dualie" omni wheels in that size, too:
http://www.vexrobotics.com/products/.../276-1902.html
2.) Any particular reason the drive motors are up so high?
Keep up the good work!