So this is pretty awesome and I'm interested in running/participating; I think my game store will be all over it as well. Some questions:
Do you guys envision this as a coherent group, or do you expect players to drop in and out? I.e., is it as casual as LFR play can be?
Given that it's one encounter per night, what provisions are made for characters vanishing between encounters? Are you planning to build in a rationale for changing party makeup for each encounter? (I don't care too much either way; I can rationalize anything.)
What level do you expect PCs to be by the time they're done with the Undermountain season?
Will future Encounter seasons also start PCs at first level? Do you envision people playing for more than one season, or is this seen as an intro without much repeat play?
Can I has cheeseburger and/or bacon?