I've been thinking a lot about the rumored ports of MK8 and Smash Wii U coming to Switch, and the more I think about it the more I think it could be a fantastic idea if Nintendo treats them like platform titles and skips new iterations for Switch. Both Kart 8 and Smash Wii U were essentially designed to be the definitive versions of their franchise. Aside from giving them maybe a bit of a graphical boost when they get ported to Switch, there's really nothing that making a brand new successor to those games in the foreseeable future would add. They should just treat the upgraded ports as platform titles and gradually add new characters and tracks/stages over the system's life cycle. As for 2d Mario, Super Mario Maker essentially elimiated the need for Nintendo to ever make a new 2d Mario again, and as such this game should also just be ported over to Switch with maybe some gradual new content updates.

Now the biggest reason I think this could be so great for Nintendo is because it eliminates most of the dev time and resources for three of their biggest franchises and frees them to make more exciting and creative new IPs such as Splatoon. To me that game proved that people are craving new IPs from Nintendo, and when they actually get behind one it has all the potential in the world to reignite their brand. They've dealt with the learning curve of making HD games and have unified their platforms under one roof with the Switch. Now is the perfect time for them to begin a new era of Nintendo and introduce some long overdue new future iconic Nintendo IPs like Splatoon is sure to become. Take a break from Smash, Kart, and 2d Mario since the pinnacle of those series has pretty much been reached for the time being, and focus instead on new ideas and I think it could do wonders for Switch. 

This is a yes and no situation.Yes because of the reasons you listed.Both games are probably the best games of each franchise, and have far more content than either franchise ever had.But I think that, if it were made into a platform, it would hurt the franchise in the long run.Or to be more acurate, it would hurt IF they are release as enhanced ports and not new entries.

I think the best solution is to have a Mario Kart 9, Smash 5, and a new 2D Mario.But make them a platform as long as the Switch lives.Or in other words, it would be a new smash/Mario Kasrt only once in a system life, and it would be adding content constantly over time.The difference betwenn my idea and your is that:

1.Making an enhance port would prejudice the franchise growth, in the sense that it would be the same as the last game and thus either get a bad reputation because of it or people not buying the game because they already played it, and hurting the Switch in the long run, since there wouldnt be any more entries on those franchises for the Switch.

2.They need to differenciate the game, and by extention the Switch, as being a new and better console.Making enhanced ports would not do that job that well, and thus could be more of a prejudice than a benefit.

Just a side note, I personally dont think the Mario Kart and Splatoon are enhanced ports.You can only enhance to a point before calling it a new entry.If it has too many new features and feels like a different game(which Mario Kart switch seems to be, with the double items and the (I assume) better battle mode), then it is a different game.

You will get

Mario Kart 8.5 and Mario Kart 9

Splatoon 1.5 and Splatoon 2

Mario Maker 2.0 and Super Mario Switch World

Super Mario Galaxy 3 and Super Mario 3D Universe

Super Smash U Special Edition and Super Smash Switch

And you will like it. ;)

Sure if they:

To Mario Kart, drop half the babies, add some actual new characters, fix battle mode, bring back the mission mode from DS. Maybe some new modes too.

To Smash, uh Story mode? that could be a thing, again more modes could help too, besides Smash Run and Tour (Tour not being that good) etc. 

Some stuff like characters and stages/race tracks could be fixed with periodical updates, tho I doubt any of them would be free, then may as well make a new game with a lot of new stuff.

About Mario Maker, I can only see it work with the Switch if it has a touchscreen, otherwise it won't be nearly as fluid and intuitive as the Wii U game. They can still do 2D Mario games, which would benefit from Mario Maker existence, basically they would need to make one with new mechanics and power ups not found in previous titles to make it more appealing.

In the end, I don't find MK or Smash to be the ultimate titles of either series, they can still tweak many things on these games (MK8 pretty much being your typical MK game only with DLC, and Smash besides DLC still has lacking features compared to say Brawl).

No thanks. Mario Kart 8 may be the best Mario Kart title to date but what makes the series truly great is the unique qualities of each entry. Even in the event that Mario Kart 9 won't surpass its predecessor there's nothing to suggest that the game won't be memorable and make Nintendo lots of money. I do believe, however, that they would be wise to use this opportunity to revitalize and properly market F-Zero while MK 8.5 "extends" the wait for a newer entry, so I don't wholly disagree with you.

And then there's Smash 4 which is simply riddled with flaws as a result of having a short development time and poor directing from Sakurai: No proper story mode, forgettable event matches, Ganondorf staying a clone, poor music selection with pretty much all worthwhile content being borrowed from previous entries in the series, edgeguarding being virtually unviable outside of specific matchups, the rage mechanic rewarding poor players, shielding/rolling/airdodging being overpowered resulting in overly defensive play (particularly in For Glory), high amount of input lag, moves doing little damage in general, little to no room for creative combos that extend beyond two or three moves, the four previous points causing average matches to last a ridiculously long amount of time, and the list goes on. Even after countless patches, no game has ever been in greater need of a sequel to fix its many shortcomings.

So it would free up most of the Smash Bros team to make games on the PS4 and XB1?

I woudn't mind that at all.

Agree, but I recall Nintendo said they will make new kind of 2D Mario that won't be NSMB, so we can again have new 2D Mario but new and fresh not just another NSMB.

Thats always what I thought Miyamoto was talking about as well. Not the 3D Mario games.

I cant recall exatly, but I think he was referring about 2D Mario specifically, but after that last few times he was saying that new 3D Mario will be different and new also.