steelydan.com yet, but the Ravinia Festival homepage show two dates for Steely Dan. August 1 and 2 according to these links:
Tickets to these two shows go on sale April 25 online here.
It's not the first time Steely Dan will play Ravinia north of Chicago, so the choice of venue is no surprise. All we need to know now are the rest of the dates. And the name of the tour!
But it looks like the rumour of a July - October 2013 tour just might be correct.
Steely Dan last toured in 2011 with the Shuffle Diplomacy Twenty Eleven tour.