Charlie Miller, the winner of the PWN2OWN contest at CanSecWest 2008, has predicted that Safari will be the first browser to fall in this year's contest.
(Miller and Dai Zovi are presenting on "Hacking Macs for Fun and Profit" at CanSecWest 2009 on March 19.)
It's not that Apple is unaware of these problems. Dai Zovi pointed out that the version of OS X running on iPhone is not vulnerable to the methods he used in his demonstration.
Things will be more difficult once Mac OS X 10.6 Snow Leopard arrives, as its version of Address Space Layout Randomisation will be much more effective (making it far harder to determine the location of specific routines), and writable memory will be marked as non-executable.
The next SOURCE conference is scheduled for September 21-22 in Barcelona.