Upper Deck Entertainment has announced plans to release a series of expansions for its new Legendary Marvel Deck Building game.  The company is planning what it calls "A Legendary Expansion Release Timeline" or "A.L.E.R.T." program that will feature one "big box" expansion set releasing before August each year, followed by a “small box” expansion every few months. 
The big box expansion is expected to include about 350 cards, including heroes, villains, masterminds, and schemes.  These expansions will feature major storyline events from the Marvel universe.  The small box expansions will have about 100 cards, including new teams, villains, and schemes.
Upper Deck has not yet announced what content will be included in the first expansion, currently planned for August 2013, though the press release hints that it will include the X-Force and Marvel Knights.
Legendary debuted in November. For details about the release, see "'Legendary Marvel Deck Building Game'."