Registration opens for MMS 2010 on November 3, 2009.
If you want to stay in the Venetian Hotel or with the Palazzo Hotel you need to book early!
If you think you want to present but you still want to attend if you don't then go ahead and register. If you become a presenter then they will credit your registration and hotel fees.
Nov 20th might be close to when the Call for Sessions opens, that is my guess. Just keep watching the mms site: http://www.mms-2010.com/ or the www.myitforum.com pages for more information.