There's a huge difference between sequels and an entirely different franchise, though. Sure, Donkey Kong plays a lot like Mario, but it definitely isn't the same. I don't think 2D Mario bars success for all future 2D platformers.
Heck, take Wii Sports Resort as an example, it did amazing well, despite essentially being a sequel of Wii Sports (though admittedly it does come with WMplus). You predict Wii Party to be huge (20 million), despite it not being so different from many other games that have already released.
I still see NSMB Wii ending well over 20 million sales, so I don't think expecting DKCR doing just under half that is too crazy, but we'll see.







