Patch 12 Released
Patch 12 had very few changes to each race, but had significant changes to Terran and Zerg. The Protoss received several changes to the Forge and Mothership. The changes to the Forge will no doubt make it easier for Zerg or Terran to break down walls created by Protoss fast expands or Voidray builds.
The change to the Thor size and radius will greatly increase its maneuverability on the battlefield. This change has been talked about for several weeks now and has finally been implemented in this patch.
The increase of the Roach supply from 1 to 2 will greatly effect the army composition of Zerg armies. This increase will make Roaches harder to mass, but their effectiveness mid-game should remain the same.
Players will also be relieved to know that a bug that caused the game to crash when exiting has now been fixed.
Battle.net - Source