Flash Player 9 April 2008 security update
Adobe have posted an article informing those in the Flash community that there's a security update coming next month, and advised developers to subscribe to their security notification service.
Most of it seems to affect socket behaviour, which I unfortuately haven't had much experience with so far (except for pottering around with SmartFoxServer at home and multiplayer tile-based game mockups), but looks like some older swfs (Flash 7 and below) played out in the new player may experience issues.