Super Mario Maker will be the WiiU's biggest, fastest seller yet
Here are my reasons:
-2D Mario is the lifeblood of Nintendo. It really is bigger even than Mario Kart (shouldn't that be obvious?). It's the best-selling series of Mario games - even while 3D Mario games like SM64, Sunshine, and Galaxy are more critically acclaimed, 2D Mario is the Mario most people identify with and are just more likely to buy. Identifying with the likes NES/SNES 2D Mario only makes the game so much more appealing to the masses including an older generation that may on the fence about the WiiU. If Nintendo was willing to launch a MK8-scale marketing campaign for Splatoon - just imagine how much they're willing to spend on marketing Super Mario Maker - something that not only is fresh during the holiday season, but is also a mirror to the company itself.
-It's launching on newfound goodwill of the WiiU. While fanboys rage and vent - the rest of world, who are largely immune to the outrage over the Nintendo E3 direct and previous struggles of the WiiU, have now seen the likes of SM 3D World, Smash, MK8, Splatoon, and other upcoming 'new' games hit the system. To people on the periphery of gaming (which is really the majority of buyers IMO), the WiiU has finally gotten started.
-It hits the holiday shopping circuit EARLY, but not too early. Provided there's no delays, Super Mario Maker launches September 11th. Compare to other previous WiiU September releases like Wind Waker HD, Rayman Legends, The Wonderful 101, and Hyrule Warriors and it's pretty obvious Super Mario Maker stands tall above those games on system-selling potential. While Mario Kart 8 caused a legendary boost in WiiU sales, it had to straddle the typically dry summer season for selling gaming hardware and software.
-Because it'll likely coincide with the overdue WiiU pricecut. 2 years and no official pricecut? Barf. Expect one by the time Super Mario Maker launches.
-Because it'll be a huge hit on Twitch/YouTube, despite not having native features for either (which we can guess will get added in some way after the game launches)
-Because it has an awesome physical package
-Because it gives good reason to promote a new series of Amiibo. While fans and enthusiasts are upset with the shortage of various amiibo, Mario amiibo really isn't one of them typically. Probably because Nintendo probably focuses on stocking Mario amiibo above anything else. And if you do the math, that's probably the kind of Amiibo Nintendo will always make the most money on - regardless if they continually restocked the 'rare' amiibo. Selling out what's by far the #1 amiibo series long-term (in terms of sales) is probably Nintendo's top priority. Positioning 8-bit mario amiibo in the market == bigger campaign for Super Mario Maker.
-Because its adjacent releases are pretty strong too. Again, while the MK8 release gave the WiiU a considerable boost it was followed up with practically nothing for months at retail. Same kind of story for Smash U - nearly all of it's follow up releases were *after* the holiday. System sellers are games that can start some momentum, but if there's nothing else to push and if it's not the best time to push - their effect is obviously diminished. The biggest, best system sellers often have something else big compounding their growth in the short-run. The likes of Disney Infinity/Skylanders plus Ninty's 1st party games (Yoshi, Xenoblade, etc) should help Super Mario Maker garner a big audience in the weeks that follow SMM's release.
-Because it's launching when the active userbase of WiiU is strongest. Even some of the most diehard WiiU fans will admit they're not sure how much time they'll spend on the WiiU 2016 and beyond. But for now, there's a enough games with a firm release windows and existing games with new features (Smash, MK8) that there's a decently large crowd of folks forming a network of WiiU gamers that will give Super Mario Maker a lot of really strong word of mouth.
So, I predict by Jan 1 2016 - Super Mario Maker will have shipped+digital over 4 million units (assuming there isn't a signficant delay)
I predict NX launches in 2017 - not 2016