StarCraft 2 makes North America a 'public test region,' live now
Like World of Warcraft before it, Blizzard revealed its "public test region" program for StarCraft 2: Wings of Liberty, giving Zerg-rushers and Zealot-sneakers an early preview of patches yet to come. First up, patch 1.20 is available for PTR participants, giving players hands-on with Battle.net chat channels, editor improvements, and forthcoming balance tweaks (among many, many other things). There doesn't seem to be a limit to the number of SC2 players able to participate, though the FAQ stipulates "players must have an active StarCraft 2 North America game account created before November 11, 2010 -- the player's account must not be a guest pass account, suspended, or banned."
According to ShackNews, Blizzard's SC2 public test region program will "conduct public tests for most if not all future game patches." As for how long patch 1.20 will be available in preview? Like most things Blizzard, it won't be available publicly "until we feel the patch has been appropriately tested."
