Apple is now placing more limitations on outside programmers with regard to what software can run on the iPhone. The new rules mandate that app developers must use Apple’s programming tools instead of other services. This creates a serious problem for programmers using other systems, like Adobe, that can generate a version of the app for the iPhone as well as other devices. While Apple wants to encourage the development of apps, developers from now on may only do so on the Apple platform.
These changes are putting some app developers on hold as they determine whether compliance with new standards is possible. For some companies the new rules will result in a few minor adjustments but for others, pre-existing agreements with other services will make compliance far more difficult.
The new programming rules are partly the result of a substantial shift in Apple’s main source of revenue. Mobile devices are becoming a more significant source of revenue than desktop computing, and there is far more pressure on app developers as a result. While some argue that new standards will promote the development of quality apps, others contend that these changes will ultimately stifle creativity.
Source: http://www.nytimes.com/2010/04/13/technology/companies/13apple.html?hpw