That should really not be a problem. Websites and apps can detect and load appropriate images for 2x or 1x displays. Same for apps. You design for 2x, and downsample for 1x.
Native apps, maybe, since you'd probably have to include both versions in your download. But surely its a bandwidth saving for web apps? You just let the browser download the right size image. Now your low res users get low res icons, while high res users get high res icons. Less bandwidth than just sending everyone the high res icons, or both sets.
