It's funny, while reading this thread over the passed few days or whatever I've been thinking "D2 is a whole lot more corrosion resistant than other people think. I don't know how these people are getting it to rust like this..."
Last night I pulled out my one Civivi fixed blade in D2 and lo and behold, the edge was all rusted to hell. Everything else on the blade was perfect, but along both of the edge bevels a decent amount of rust had formed. I took it first to my basswood strop to knock the bigger stuff off and then to leather and got it pretty damn shiny again, although I will have to give it an actual sharpening to get rid of it all. It is just small surface rust, but enough to where stropping for a few minutes alone didn't get rid of it all. The last time I carried it I was camping at a beach on the ocean in the pacific northwest. I don't remember even really using it, however I did have it out of the sheath and took some pics of it sitting on a coral bed further up the beach. Either way it was enough to give it a nice little coating of corrosion along the edge. Not a big deal at all as I need to reprofile it anyway, however just something to note that surprised me.