I don't think it will, but its possible.

Yoshi's Wooly World will be a success for Nintendo, however, Xenoblade Chronicles X and Splatoon have more appeal.
The Wii U already has a stellar 2D platformer lineup.
People will likely dip into the genres that have had less attention, as well as potentially drawing in new buyers for the Wii U.

Yoshi will definitely outsell Kirby hands down.
It is somewhat difficult at this point to determine if it will outsell Xenoblade and Splatoon. I am leaning towards that Splatoon will be the best seller out of the three (Yoshi, Xenoblade, Splatoon).
Even though Xenoblade is the one I am looking forward to the most, I believe Splatoon has the potential to be a hit.

Yes.
Because it's Yoshi, a Mario character.

I'm gonna say no.

Splatoon and XCX are the "heavy hitters" and even that is yet to be proven. Yoshi will not do well by comparison.

I don´t think so.

Will outsell Splatoon, not sure about XCX though.

Yoshi is pretty big in Japan, XCX and Splatoon are not. Yoshi is a pretty safe bet to sell at least decent in the west as well. Splatoon is a big question mark, we can see it's not getting that much hype in Japan and we really don't know how it's gonna do in the west. XCX will not be huge, but it could reach 700k-1m.
I think 1m is the floor for Yoshi, probably more like 1.5 or 2 lifetime realistically, while i think 1m is more like the ceiling for XCX. Splatoon has more potential but it's gonna take a lot of effort to make it a big hit.

no for both

I actually think it has a decent shot; it's the most established franchise of the three.