During a conference call with investment experts, Adobe's chief Shantanu Narayen said they are currently developing their own Flash client for the iPhone, and this didn't happen before because they are using the iPhone SDK to help their efforts, and the SDK just became available. The intention is to use the App Store to release a version of the plugin as soon as it's done, but the question remaining is "When?"
Unfortunately, there's no answer to that yet, so I guess we should wait for a while, especially since Apple's limitations(third-party software can't run on the background on the iPhone) force the iPhone Flash "plugin" to be a standalone application...