I switched to an aluminum winter bike back in '95 here in Minnesota because of the salt. It's handled it much better than the steel bike it replaced. The fork is chromoly however, and as chriskmurray mentioned, painting spots as necessary is the key.

A mental shift I went through many years ago was convincing myself that the drivetrain is a disposable item and not to beat myself up for not keeping it pristine. My winter bike gets a fifth the miles that my summer bike gets, but they've gone through about the same number of components. "What's your time worth?" is the question only you can decide. The increase in winter maintenance costs for me is still far cheaper than driving, so I don't get bent out of shape over it any more. (Well, mostly. I still have those moments of seeing it in the garage and cringing, thinking "you poor bike...!" But it's seventeen years old with over 18k hard miles on it and still works like a charm, so I'm not neglecting it too badly...)