There is an expectation amongst consumers that apps will run in their native resolution. Have you tried running standard iPhone apps on an iPad screen? They look less than impressive. Coping with a higher resolution is fine for larger companies but for indie developers it alienates them from the app store to a certain extent and they are the people who essentially fuel the appstore. From a programming perspective it isn't too difficult to adapt to but from a graphical standpoint it can require a complete graphics overhaul in order to cope with the resolution.