Found an interesting and informative link here. NHLSCAP.com has joined with hockeybuzz.com, and they provide salary cap information for all of the NHL teams. This page shows the current salary situation the Blackhawks have. According to them, the 'Hawks currently have an actual payroll of about $39.8 million for the 2008-2009 season, and have just a shade over $13 million of cap space left to spend. Seems like a pretty good amount left over for now that they can use on free agents, so hopefully they take advantage of it.
Good link to keep in mind, I usually find it tough to find information on cap situations and such, but this page basically tells you everything you need to know regarding how much they've spend and how much they have left to spend.