Edit: however, the infested terran nerf & map changes from the situation report of January 11 have gone live at the same time:
Note: This balance change went into effect in StarCraft II: Wings of Liberty at 12:15 p.m. PST, January 15, 2013.
First, we’ve decided to alter the start location rules for Antiga Shipyard and Entombed Valley to match those of popular tournaments. From now on, starting locations on Antiga Shipyard will be locked to cross-positions only, while Entombed Valley will allow players to spawn only in vertical and cross-positions.
Zerg
Infested Terrans no longer gain weapon and armor upgrades.
First, we’ve decided to alter the start location rules for Antiga Shipyard and Entombed Valley to match those of popular tournaments. From now on, starting locations on Antiga Shipyard will be locked to cross-positions only, while Entombed Valley will allow players to spawn only in vertical and cross-positions.
Zerg
Infested Terrans no longer gain weapon and armor upgrades.
StarCraft II: Wings of Liberty patch 1.5.4 is now live. This patch includes systems improvements and bug fixes.
Read the full patch notes below to learn about these changes.
Bug Fixes
General
Several improvements have been made to address an issue where players would load into a game slightly later than other players. Additional details regarding this are in this forum thread
Fixed an issue that occasionally caused stuttering in the middle of a game.
Fixed a rare issue that caused prevented players launching the patched client without an Internet connection from accessing features in Offline Mode.
Fixed an issue preventing some custom minimap icons from displaying properly in Arcade games.
Editor
The trigger module should no longer stall for long periods of time when adding or removing actions.
Races
Protoss
Structures built within the power field of a Pylon of an ally who disconnects should no longer remain powered when that Pylon is destroyed.
Read the full patch notes below to learn about these changes.
Bug Fixes
General
Several improvements have been made to address an issue where players would load into a game slightly later than other players. Additional details regarding this are in this forum thread
Fixed an issue that occasionally caused stuttering in the middle of a game.
Fixed a rare issue that caused prevented players launching the patched client without an Internet connection from accessing features in Offline Mode.
Fixed an issue preventing some custom minimap icons from displaying properly in Arcade games.
Editor
The trigger module should no longer stall for long periods of time when adding or removing actions.
Races
Protoss
Structures built within the power field of a Pylon of an ally who disconnects should no longer remain powered when that Pylon is destroyed.
http://eu.battle.net/sc2/en/blog/7029173/