Prediction: SSBU/3DS 10mil Shipped Together By Years End! (or Close to It!) UPDATE: 9.58mil Shipped :-D

[HylianSwordsman]

Not by years end, but lifetime most definitely. The 3DS version alone will probably have over 5 million by years end, and the Wii U version should be approaching 3 million by then at least, so probably over 8 million combined, I'm thinking.