According to this post (coral) from iMobileCinema, they’ve released a beta version of a flash plugin for MobileSafari. Unfortunately, it’s video-only – any site that uses flash to deliver video, such as youtube/vimeo/revver/blip.tv, can be supported, but it’s no use for interactive flash.
If that still makes you happy (I’m certainly not complaining), you can just add the source d.imobilecinema.com to your cydia sources and download as usual (your iPhone IS jailbroken, right?).
Happy flash-video-watching, here’s to hoping for a real version soon!