The Battlefield 3 Premium service will be offered from Monday 4th June for £39.99 / €49.99 (the day when E3 2012 kicks off). According to a leaked specification sheet, the premium service will get you access to all the DLC early, increased soldier customisation and get a number of exclusive in-game items.
There’ll also be Premium-only events, exclusive double-XP weekends, strategy guides and tips and server queue priority. EA have yet to confirm the details themselves, but be sure to expect an official announcement soon.