That's not necessarily true, it depends on your app. Game developers in particular (i.e. apps not using standard Apple-provided UI elements) are going to have the hardest time. For these apps (which is a very large percentage of those available in the App Store), supporting different aspect ratios is considerably more difficult than supporting other resolutions at the same aspect, although it really depends on the content. If you have an app that uses standard list views, scroll views, tab bars, etc., then yeah, it wouldn't be a big deal. But it could be a huge PITA for game devs, especially independents who don't have the resources to meticulously tailor all their artwork to every aspect ratio. It'll have to be done of course, but it's potentially a huge time sink, time that they spend not coding new apps.