We've learned more information today, and this isn't going to please people who hate the MLB blackout rules.
During the primetime schedule, [including 10 straight weeks between May and July] all games scheduled between 7 and 10 PM EST will air on FOX locally and be unavailable to watch on MLB Extra Innings or MLB.tv. Normally, FOX blackouts only take out three afternoon games at a time. During the primetime periods, the blackouts will take out five or six games at a time.