There's no real reason to panic yet. There's a lot of hit series with original cast members that could be the actual victims of the dreaded axe. And after all of the denying, it would really affect Shonda's credibility if they turn around and fire Heigl. So for some reason, I find it hard to believe that the blind item pertains to Izzie.
But what's Ausiello trying to tell us? Anyone? Bueller?