Direct link here (thanks NintenDaan!)
This DLC pack is now available in Japan, costing the lovely price of 0 yen. That's right, the pack is free! It won't be that way forever, though. After Jan. 31st, the price will be raised to 200 yen. Levels are based on classic Mario stages, including Mario Bros. Round 1, SMB1 1-1, 1-2, 1-4, SMB3 1-1, 1-5.