I have one property in Chicago, its a great City and is bucking the trends, particularily in the rental market with rents up almost 2% during last quarter ( source - Crains journal ), buying on hope for Olympics isn't a good enough reason to buy, decision is due late 2009, whilst property may have slowed there is still strong demand, main out of country investors are from South America and China according to the locals, also domestically popular with suburban Chicago dwellers and Calafornian buyers.
Do the inspection trip, be very careful though as like any market there are areas to avoid, concentrate on Loop, West Loop or something with lake views, do go see the place, its well worthwhile, gather information in advance to make the trip worthwhile, if nothing else you will love it as a City break..