I'll be at E3 but I don't think I'll be protesting.
Incidentally how do people plan on getting into E3 to protest outside their booth? Not only is E3 a for-press-only event, but LucasArts hasn't even got a booth out on the main show floor. Their "booth" is always just a very decorated large meeting room in a side hallway, so from the outside there's just a door in a hallway with a little sign on the outside that says "LucasArts."
That said, I hope people somehow manage to pull this off though, as it would be a pretty brilliant infiltration of E3 and would surely get some press attention, E3 being a press event and all that.
thanks serialfreak for beating me to it