Some foods were always gluten free. Hormel brands had a number of items that were close to being gluten free, and now many of them are labeled as such. Useful when I want to make a quick chili and cheese chip dip. (Superbowl party, here I come.)
Betty Crocker also produces a gluten free line of baking goods. Its still fairly expensive compared to their regular mixes, but nice that a regular store will carry them.
Progresso is who/what surprises me, when they completely replaced their normal line with a gluten free product. Particularly their clam chowder and cream of mushroom soup. Not a second line, but completely replaced, without making a large price change either. Yes, I know they've all been out this way for a while.
I still like going to my local Whole Foods, and even Trader Joes to pick up gluten free foods, but those stores are not everywhere, so it's still a nice change, knowing that wherever I am, I can probably get a can of Hormel Chili, or Progresso soup, or Betty Crocker baking mix.