Your take on Millennium Park is pretty accurate. Mostly it's to look at, but there are concerts and such occasionally. It seems overrated to me, but others differ.

Just to clarify, Tut doesn't start at the Field Museum until late May. I was talking to them last week and they had presold 147,000 tickets out of an expected 950,000 for the whole run.

The Metra Electric line to the Museum of Science and Industry is IMO superior to the #10 bus, although it doesn't operate as often (about hourly during the day, every two hours on Sunday, more during rush hours), so check the schedule carefully. Remember that the #10 bus takes Lake Shore Drive (unless their online map is wrong), which is overrun now with people avoiding the new Dan Ryan (I-90/94) construction. The train has only a few stops and takes about 18 minutes.

If you like bookstores, there are a couple good ones less than a block from the 55th-56th-57th Street station, which is the one for the museum. Powell's and O'Gara and Wilson are less than a block from the station, in the opposite direction on 57th from the museum.

Science and Industry has a stunning Omnimax show right now called "Greece: Secrets of the Past."