I've been riding through the same crummy New England weather. I recently started using White Lightning chain lube, the "clean" version. From what I can tell it's basically a solvent, with wax dissolved in it. You squirt it on a clean chain, and the solvent carries the wax in to the rollers, then evaporates, leaving the wax to lube the chain. The thing I like most about it is that since the chain isn't greasy it doesn't collect grime from the road. This means that you can just squirt more on later, without having to clean the chain.

I only started using it about a month ago, and so far so good, but I can't comment on how it affects chain life.

As far as the rust goes, a little surface rust isn't going to hurt anything. However, you do want to clean you chain more thoroughly than with a hose every now and then. You can either get an on the bike chain cleaner, which is a plastic housing with brushes in it. Or, if your chain has a quick link, you can just take it off and soak it in some degreaser.

Chris