Ref:
The WD40 post Did the search, and all results seems to say WD40 being "formula to prevent corrosion", but I guess it's use is meant for stored items. But agree that's it's not a (good) lubricant (no long term function).
http://wd40.com/about-us/history/:
Convair, an aerospace contractor, first used WD-40 to protect the outer skin of the Atlas Missile from rust and corrosion.
Regarding salt, here in Norway it's used profusely in the cities, cars sometimes wading in a mess of salt\water\sand\half-melted snow. And many cars here rust to pieces early due to this.
Before, I did some winter riding, the corrosion attack to aluminum, rims, chrome etc was horrible, even when trying to avoid the obvious salting periods (there was salt residues everywhere). Bike would need a complete wash & clean after each trip, which was not done that often.