It would be fun to set up a tournament that starts with six groupings of teams (or more depending on how many players we could get involved), and then the winners play each other, but they can use their heroes from the prior game...maybe not the first hero in the game, but they arrive later on (kind of like how campaigns worked in Warlords).
Or some type of a team campaign grouping of maps would be really fun where the heroes get carried over.