There will be starter sets, as well as booster packs. Plus, there will be the deluxe Collector's box, with exclusive cards and dice inside.
From the post:
The greatest heroes and villains of the DC Comics universe will come alive in the Dice Masters arena this spring with WizKids Games’ inaugural DC Comics Dice Masters release – Justice League!
As many comic fans know, the Justice League handles threats too enormous and terrifying for any lone hero. The team is much greater than the sum of its parts, as incredible as they are. This spring, the premier release of DC Comics Dice Masters from WizKids Games will bring the most awesome DC Comics heroes and villains to another gaming platform! Whether you decide to embrace the power and teamwork of the Justice League, or the evil plots of the Legion of Doom, there is a lot of excitement to uncover!
This first release of DC Comics Dice Masters brings the heroes and villains that shape the DC Universe to the forefront of Dice Masters. Fan-favorite heroes of the Justice League such as Superman, Batman, Wonder Woman, Aquaman, Martian Manhunter, Cyborg, The Flash, and Green Lantern show up in multiple versions, each keyed to a different strategy and playstyle. Some are designed to work well with each other, while others function a little more independently. In addition to the Justice League, the Justice Society of America also makes an appearance - Stargirl, Red Tornado, Hawkman, and Green Arrow won’t disappoint new or old Dice Masters fans!