Are you implying that MK8 just stopped selling? 

Im pretty sure Nintendo have said that Mario Kart 8 has passed 3 million. Smash will be a success too.

It's one of the highest selling franchises in the world, of course its going to good things for the wii U. Not to mention its coupling up with Amiibo which I think is going to net Nintendo a tidy profit.

Wii = Most Casual Console.    I mean Look at this from GCN to Wii   [SSBM 7mil to SSBB 12mil]  [MKDD 7mil to MKWii 36mil]

SSBU is definitely going to push alot more systems than MK8 did

Smash is a system seller which with the combined pull of MK8 can increase the baseline further, Brawl itself sold heavily in its first few weeks then went on to sell 12m over the following years. MK8 has broad commercial appeal while Smash has a strong dedicated fanbase.

Mario Kart sold 2.82 Million in less than a month. Those Numbers are from June 30th. The game still among top 10 sellers so the game at this point has easily surpassed 3 million and is likely closing in on 4 million.

Smash has a lot going for it. First one in HD. Surprising roster additions. A 3DS version. Amiibo as figures sell and Nintendo giving away sound tracks for the game. They likely will do a bundle as well for Wii U. I would not be surprised if it sold over 1 million within the first month. That's being very conservative

It will increase the baseline even more....

Obviously.

I am waiting on Smash to buy a WiiU... I may even buy one this week so I don't have to worry about not being able to find one come the Holiday season. I will still be buying it for Smash though... that won't change.

It was 2.82mil shipped+digital in 32 days. I expect sold should easily be over 2.5mil by now and 3.5mil shipped+digital.

That doesnt do anything but prove that mario kart would sell more systems.  If you go back to nintendos hardcore console the gamecube (even though that is way too far back to have any meaningful co parison to today) they sold essentially the same amount (even though mario kart had less time on the market). So if anything, they would be equal in terms of system selling capabilities by your argument. 

However, casual/hardcore doesnt mean anything.  It is vague and general and is used to justify an unsubstantiated opinion.  Fact is, smash on the wii u is actually poised to have the least system selling capabilities for the home console of any smash game before simply because it is splitting potential custumers between the wii u and 3ds.  

Smash will sell well and sell systems, but it isnt going to have nearly the effect mario kart had if for no other reason than the 3ds version exists and will pull sales away from the wii u...