I called today to see what dates were available:
June 3-8 and June 24-29 in the Payload Specialist Tracks were the only dates available.
If you want to go in the month of June, I suggest you hurry and give them a call at 1-800-63SPACE or register online.
I guess I for one will not be going, due to both those dates being quite bad for me, and my being too old after June to go. *sniff*
Hurry if you want to go!