First, Microsoft is now issuing refunds to affected customers who contact the publisher through customer support. Second, it is preventing other customers from being Mineshafted by adding clearer notification to the XBLA listing: "To experience split-screen functionality a high-definition television is required."
Microsoft statement regarding Minecraft XBLA refunds:
"We updated our pre-sale notification to inform customers that an HD screen is required for the split-screen multiplayer feature on Minecraft: Xbox 360 Edition. If a player does not have an HD screen and purchased this game prior to the notification update, they are eligible for a full refund through customer support."