How cool to see the GenCon League and the Tournament listed on the GenCon events schedule.

Is there any description of what is involved in these two events? I'm trying to plan GenCon well in advance so I don't face a sell-out situation and have time to pick up cards, play test, etc.

Maybe I should clarify my questions:

What are the formats of the "League" and the "Tournament"? Will it be LCG only? Will League have build restrictions?