That was a surprise: I downloaded IntelliJ 8 preview (Diana) and after it compiles, it uses Growl (the centralized Mac notification app) to inform me that its completed. Nice.
I'm also experimenting with using the Mac OS X look and feel (rather than Alloy). I had used Alloy in the past for performance reasons but IntelliJ 8 feels a bit faster. In addition, it's nice having the menu bar be where it's supposed to be ... the Mac look and feel puts it on the Mac menu bar, but Alloy puts it, Windows-style, in each top-level frame.