The question has been closed for the following reason "The question is answered, right answer was accepted" by Tim Fontana Nov 14 '10 at 15:45
You don't just get more. They are rolling out the beta slowly so as not to overwhelm their developers. This is the reason they are "throttling" the number of invites you can hand out. Patience! It will be public soon enough, and then everyone can get it.
answered Nov 14 '10 at 15:35