There's one unknown factor here, and that is the word "new". For example, Tales of Symphonia: Dawn of the NEW World on Wii sold less than just Tales of Symphonia on GameCube. This could also be attributed to the words "Dawn", "of" "the" and "World". It's probably "World", since "Super Mario World" sold less than "Super Mario Bros.". But numbers decrease the effect, because even with the "World", Super Mario World outsold Super Mario Bros. 3.
Notice that none of the Wii's top sellers have numbers in their names, despite many of them being from long-standing series.
EDIT: Wait, there is Mario Party 8. Well, that is simple. The word "Party" increases sales with the number 8, because there is food at parties, and 8 = ate, so I 8 the food at the party. See how that works? So this game would sell even better if it was called Super Mario Bros. Party 8 Wii. Or, actually, Wii Super Mario Bros. Party 8, because having the Wii at the front increases sales.