i've done the winter bike thing in chicago for 4 years now. the first two years were with an old "hybridized" 90s MTB, the most recent two years were with an IGH/disc brake hybrid.

my thoughts:

- i found studded tires to be invaluable after some bad wipe-outs on glaze ice in my first year.

- fenders are your friend.

- i'll take disc brakes over rim brakes for winter biking. others will swear that their rim brakes work just as well, if not better, than disc brakes in winter's messy glop, but that has not been my experience at all. not even close.

- the IGH on my current winter beast is neat and all, but it may be overkill for chicago because the streets are kept pretty well plowed here. a traditional derailleur drive-train will probably serve you fine. you could maybe even entertain thoughts of fixed gear as many winter riders seem to like it for better control of the bike.

- i'm thinking about possibly upgrading to a disc brake CX bike for winter commuting. the IGH thing isn't my favorite, and i prefer drop bar road bike geo's over hybrids.