Pre-register at Comicopia
Anime Boston will be at Comicopia on September 12th from 1pm-5pm. You will be able to pre-register for all 3 days of Anime Boston at the $40 rate. There will also be a 10% off manga sale on the day of the event.
While no date for online registration has been set yet, this will definitely occur before online registration is up, however registration will be available for $40 when it does go online.