Ben Trott has sent out an email to everyone who bought a license for Movable Type 3.0 or who requested more information about the MT Developer Network, with information about the beta test period of Movable Type 3.1. Those who received the email were invited to fill out a form to show their interest, and names will be picked at random for the test.
Testing starts on Monday, ahead of the final release at the end of this month, with these new features included.