This comes from Serkan Toto, the CEO of a Japanese game industry consultancy. 

1) One day to go until Nintendo’s first of two briefings this week. The first app will use existing IP, but don't expect too much from it.

— Dr. Serkan Toto (@serkantoto) October 27, 2015

2) Don't get your hopes up too high for Mario. But I heard Nintendo and DeNA are planning to pull out the big guns (bigger IPs) next year.

— Dr. Serkan Toto (@serkantoto) October 27, 2015

3) About the membership service, I heard technical challenges made a roll-out earlier in the year impossible (well, this isn't trivial).

— Dr. Serkan Toto (@serkantoto) October 27, 2015

4) Another point: according to my sources, Nintendo+DeNA experiment with different business models, so non free-to-play apps are possible.

— Dr. Serkan Toto (@serkantoto) October 27, 2015

Well, what do you think? Sounds like Nintendo's first mobile game won't be anything spectacular. 

I expect Tingle's Rosy Rupeeland 2.

Just give me my Endless Super Mario Bros 1 runner...

That's a bit tricky because if it's not spectacular it won't become massive, then it won't make people want the 3ds or wii u as their plan is supposed to be. So, I think it will be something very good but not something like Super Mario 64 or Galaxy were back in the day. It's a mobile game we are talking about, how spectacular can it be anyway? I haven't played too much on my smartphone so I don't know how impressive games can be.
What they should go is it to be addicting so everybody downloads it, they make billions in profits and then they can spend all that money making good games for NX :P

Mushroom Kingdom Crush, Marioggle, Angry Kirbies, and a game where Pokemon are depicted as cute/sexy girls who turn into battleships.

Insider Confirmation:

btw Pokemon Shuffle reached 4 million downloads yesterday.

This says nothing much.

A lot of rumors there, will wait and see if they are accurate..

Interesting...