New Super Mario Bros. 2 announced for 3DS!!! Hitting the World and eShop(!) in August!

[Cheebee]

So... This is the 3rd New Super Mario Bros. game, yes?

Then why are they calling it '2'?
What, the Wii game doesn't exist anymore? Was that game some sort of spinoff?
I honestly don't understand and think it's a very weird and illogical choice.