Pardes - your Trek 7.2 will be just fine until we get snow. Then.... do you really want to be riding your bike? If so, change the tires to something with a little more agressive tread (snow tires if you will). Or give yourself a break and wait for the snow to melt before venturing out again. If you really really want to ride in snow, wide knobby tires, the biggest that you can fit, and FENDERS will make winter commutes bearable.

For more, check out the Ice Bike thread in Bike Journal - there are many many posts there by people that do this every day in very cold climates.

But really, your bike will serve you well.

Now if you are looking for an excuse for another bike, and have the space to keep it.... by all means, get a beater bike and studded tires if you like for the snow. But I can hardly believe you would want to buy a nice new bike and ride it in snow and salt... and then have to clean the bike every couple of days for the pleasure of riding in the snow. Remember how messy your car gets when driving in slush? Transfer that to you, your clothes, your panniers, the contents, not to mention your drive train.....

For more, see the Ice Bike website:
http://www.icebike.org/

The clean up alone keeps me from riding voluntarily in the rain/snow. If it happens while I'm out there that's one thing, but ......