The Pokemon Company will release the XY-Flashfire expansion set for the Pokemon TCG on May 7th.  The release will include Booster Packs and Theme Decks.
This more than 100 card set focuses on Fire-Type Pokemon, and introduces the Mega Charizard-EX (two versions--one Fire Type, one Dragon type), as well as three other new Pokemon-EX cards.  There are three new Mega Evolution Pokemon, as well as over 25 Pokemon from the Pokemon X and Pokemon Y video games, and 15 new Trainer cards (Item, Supporter, and Stadium cards).
The 10-card Booster Packs have an MSRP of $3.99.  The 60-card Theme Decks have an MSRP of $12.99.