I have steadily stocked up over the past 5 years. Not because I am particularly concerned about any ban, but because I'm tight with a dollar. I keep an eye on craigslist for people selling ammo below market (I just bought a bunch of Wolf 45acp for 26 cents a round yesterday), and tend to buy in bulk if I'm buying retail-- you usually get a better price per round if you do it that way. The way I look at it, ammo isn't getting any cheaper, when you take the long view. It's good basically forever, and has an intrinsic value, unlike the dollar. Some of my family calls me a "bulkoholic", but I just don't like paying retail.
**For anyone looking for 7.62x39, www.ammoman.com
has 1000rd cases of Wolf Performance HP ammo available for $299 shipped. This caliber is hard to come by at any price, and even though it's priced higher than I've seen before, it's cheaper than you're likely to find at a gun show nowadays.