Mayday 2011 is the 125th anniversary of the Haymarket incident. My vision is to have unions, socialists, Marxists, communists and anarchists from all across the world to come to Chicago for a parade that is even larger than the one that lead to the Haymarket incident.
From Wikipedia:
The movement's center was in Chicago, where an estimated 40,000 workers went on strike.
If we get participation from across the world I think we should be able to double that number (although my goal is to get 100,000 marching).