The best evidence of this burgeoning passion for dance could be found in the estimated crowd of 8,000 that gathered in Millennium Park this summer to see the first Chicago Dancing Festival — a one-night showcase of major companies from throughout the United States. Sure, the price of the ticket (free) was unbeatable, but this event (with a 2008 followup already in the works) also was a great indicator of just what a discriminating and enthusiastic audience for dance exists here now.