Spyderco's H1 is great stuff. You just can't get it to rust, no matter how hard you try
H1 is actually a rust
proof steel, not stainless. The usual hardening agent in steel, carbon, is replaced entirely with nitrogen. No carbon, no rust. It behaves a little different than normal tool steels, but I have heard good reviews of it.
I don't really worry about the steel on my knives too much, more about the handles. When I know there is potential for a wet environment, I carry a plastic handled knife instead of my usual wood handled knife. My wood handles are treated with oil to protect them, but if I'm going to be soaking the knife in rain or slush, I want to avoid excess damage to the handle.
I know that even if my blade rusts, I can just sharpen the rust off and it will keep cutting. I can see rust as more of an issue with a hunting knife, which could be used to field clean your catch, but for wood and utility cutting (which is 95% of what I do with a knife), a little rust is fine. When I get home I can sand it off, or just leave it and not care.
Check out Dan Koster's guide to steels,
http://www.bladeforums.com/forums/showthread.php?t=500049
You might also check out D2, which is a highly stain resistant, non-stainless tool steel. It holds a very good edge when properly heat treated, and seems to have a very high corrosion resistance for a non-stainless. The reason for this is that the chromium content is fairly high, but not quite high enough for a stainless classification.