It's a problem if your app depends on functionality delivered after a certain patch level, though. For example, if my application depends on some feature deliv

It's a problem if your app depends on functionality delivered after a certain patch level, though. For example, if my application depends on some feature delivered in 4.2, I need to be aware that my potential market is less than 5% of devices in the wild. On the other hand, if the app is 100% compatible with the 2.3.X line, I can count on the all of the devices working, but I also should regression test with the updated versions to make sure that they work.