If you live in a building with a basement laundry room, it's time to start making regular use of it, if not to store your bicycle, then at least to rinse it off regularly. You needn't do this after every ride, but at least once a week is ideal. Use a fat sponge and warm water (don't use pressurized water or a hose!) to remove the salty dust from your frame, saddle, and major components. With an old rag, wipe down your chain (and if you're motivated, degrease and add a few drops of chain lube).
If you ride through the winter, consider giving your bicycle a post-winter overhaul. When the weather turns (hopefully come late February) and the salty mess goes away, consider giving your bike a nice overhaul. Check the hub, headset, and bottom bracket bearings, and remove any build-up that's found its way inside your frame. (This goes double if your frame is steel.) Replace worn or crummy cables and put on some nice, fresh, slick stainless steel ones. Jet lube your housing, or replace it altogether. Maybe re-wrap your handlebars. Spring is just around the corner!
Special attention should be made to leather bits, such as toe straps, Brooks saddles, and saddle bags. Salt will eat right through this stuff if you're not careful. Ideally, you'll be riding with fenders, yes? Fenders save a lot of time and trouble, and really needn't be awkward or geeky. Even roadies with silly tight clearance can get in on some sweet fender action with a pair of Planet Bike Speed EZs ($40).
Quite honestly, your best bet in the winter is to just ride a beater, or a nice single speed/fixie with wider tires and cantilever brakes. TATI coincidentally offers custom versions of said winter rides, but that's not what this post is about. It's about the horrible mountains of salty hell being constructed in secret all around our fair city.