Mark Pilgrim pointed out that even Mozilla is having to put Flash integration on hold for their Maemo version. I am reminded of a post by John Chen in the Flash Poor Performance on Max OS X tracking bug indicating that OSX performance wasn't of primary concern to Adobe as

our highest priority will be optimizing our player to be faster than ninjas for mobile phones

The post has since been removed but I pulled it from an email update. It appears that John had revised the post and it was eventually deleted from the forums. Nevertheless the performance ninjas haven't shown up yet.