I am most excited about the all new Objective-C 2.0 support in GCC 4.6.
Phoronix: GCC 4.6 Is Only Four Bugs Away From An RC
While it's taken a while to clear out the most prominent bugs/regressions for GCC 4.6, its release candidate is now coming very soon. There's just four P1 regressions left before the release candidate of GNU Compiler Collection version 4.6 arrives...
Are we trying to be 31337? That should be a capital letter 'O', not a zero: -Ofasta -0fast optimization level has been introduced