Has this penetrated the southwest side of chicago yet...I've not been notified. And if it has, does this require a new modem or just a reboot as usual? Thanks in advance -- "When I was in junior high school, the teachers voted me the student most likely to end up in the electric chair."---Sylvestor Stallone
my suggestion might be to go to the comcast page and search by your zipcode and see if they mention ultra/extreme services. only ultra/extreme will require you to have the docsis 3.0 modem which you can have them send you or go to your service center and pick one up. it will cost you $3/mo to "rent". i have not seen them in stores yet. my modem is a motorola sb6120.
you could also search a few other threads in the forum and see what you find in terms of availability for your area.
this thread is discussing the fact that while the service does seem to be available in chicago, it is not currently configured correctly to give the advertised speeds. something that comcast will fix soon (hopefully).