It seems that Microsoft have bent space and time around their stringent guidelines and allowed the 360 version of Armored Core 4 to support the Regulation system from the PS3. The Regulations are, basically, selectable patches that change the balancing of the parts and abilities within the game. The reason why they were selectable on the PS3 version was down to the conflicting (and highly subjective) whinge-o-thons by Armored Core players on the previous games. People, with a highly developed sense of self-denial, weren’t able to look into the abyss of their wussy gaming skill and subsequently blamed “unbalanced parts” as a cause of their multiplayer demise. The Regulations allowed various players to choose which type of parts balancing they preferred, thus deftly sidestepping their carefully layered psychoses.
The 360 version will receive all three of the current Regulations (1.10, 1.20 and 1.30) on the 3rd April at about 8pm (Japanese time). Whether these Regulations will get a Western release hasn’t been specified (though I am assuming it to be highly likely).