The slowness of Flash has long been a complaint on the fairer platform and it finally looks like somebody at Adobe was paying attention. Adobe Labs has released a beta for Flash Player 10 and among the changes is a major speed boost. Indeed commenting on his personal site, one Adobe Flash engineer has gone so far as to say that "this version of the player runs... [the GUIMark] benchmark substantially better on OSX than any previous Flash Player version. It should be up to 3 times faster" (more details here).
Adobe Flash Player 10 beta 2 is a free download from Adobe Labs. However, they warn that previous version should be uninstalled before updating.