A recent interview with Bloomberg has had Adobe chief Shantanu Narayen reveal that Adobe has teamed up with Apple, to work on bringing flash to Apple's iPhone.
Narayen has said that "It's a hard technical challenge [Flash], and that's part of the reason Apple and Adobe are collaborating". CEO of Apple, Steve Jobs, said last March that the full version of Flash runs poorly on the iPhone, and Adobe's Flash Lite is not featured enough for use, so he has called on Adobe to produce a third version.
Adobe has a long history of porting technologies to mobile devices, like the previously mentioned Flash Lite, but still has to overcome some unmentioned hurdles to finally get a consumer-ready Flash for the iPhone. Narayen said, three months after the iPhone's App Store launch, that he's "pleased with progress" on Flash, so maybe it's not very far away from release at all.
It is not clear which form Flash for iPhone will come in, be it a separate App or possibly built into a future firmware version, as third party iPhone apps aren't allowed to serve as plugins, as per the iPhone SDK rules.