As part of his Silverlight 3 release announcement, Scott Guthrie stated:

Expression Studio 3 will be included as part of the MSDN Premium and higher subscriptions (meaning MSDN Premium customers don’t have to pay anything extra to get all of the Expression Studio products).

Technically Premium is the highest subscription but there are three of them: VS Pro + Premium, VS TE + Premium and VS TS + Premium.

If the implication is that VS Pro + Premium now includes the full Studio, then this is a much welcome albeit overdue upgrade, as previously only Expression Web and Expression Blend were available to VS Pro Premium – you needed VS Team Suite + Premium for the full Studio.  Also, previously only Partners at the lowest level (“Registered”) could get an Action Pack subscription (with web benefit) including the full Studio leaving Certified and Gold Certified Partners with just Web and Blend in their included VS Pro/TE + MSDN Premium subscriptions benefit.