According to Wired, Flash for iPhone will be a victim of Apple’s stringent terms of service, which specifically prohibits the downloading and use of interpreted code in apps unless the APIs and interpreters are already preloaded. But why would the company risk driving away customers by offering an arguably less capable product than their competitors?
Apple CEO Steve Jobs has stated before that Flash “performs too slow to be useful” on the iPhone, but that shouldn’t be a problem with the new version, which is said to run on any smartphone with a 200MHz or better processor and 16MB of RAM. So the real reason may have more to do with losing control and not really with performance, as while existing web applications are fairly limited, Flash is powerful enough to draw business away from both the App Store and iTunes’ music and video sections.
The dilution of control is just a part of the problem, though. Running Flash on the device could also lead to reduced battery life and periodic security holes. All said, Flash's inclusion in iPhones looks uncertain for now but Apple may have to allow it eventually – perhaps with some heavy restrictions.