The AirTran schedule extension is loaded, though no fare inventory is loaded quite yet so you can't book.

DSM-MKE ends 9/28
DSM-MDW starts 9/29

There will probably be a lot more local traffic on DSM-MDW than DSM-MKE, although Des Moines-Chicago competes against other airlines while DSM-Milwaukee is a monopoly. Of course AirTran has very limited connectivity at Midway, so they're probably banking on the code share being ready by then.