By now, you've probably heard the news: The European Commission (EC) wanted Amazon (AMZN 0.66%) to make unspecified concessions to allay its concerns that allowing the e-commerce giant to acquire iRobot (IRBT -7.65%) wouldn't hinder competition among manufacturers of robot vacuums. iRobot refused, making it unlikely the EC would approve Amazon taking iRobot in house. And today, Amazon made it official: It's walking away from the merger, and is in fact so uninterested in acquiring iRobot at this point that i ...