The fourth series of the Transformers Trading Card Game has been officially revealed by IGN and Hasbro, for release in November.
It will be called "Siege 2" (or "Siege II" on the packs), and the booster packs will follow the same format as the first Siege set, in which they have a large character card, a small character card (Battlemaster, Micromaster or half of a Weaponizer), and 6 battle cards.
The feature of this fourth series, is that every master carton (of 30 booster packs), will have a Trypticon card pack included, which has a Titan card (Trypticon) and three "large" character cards (Brunt, Fulltilt and Wipeout - which I think is the first time Trypticon has been associated with both car minions, when it is usually just one or the other).