From a tech standpoint, it would only be possible for Android apps since Android is a middleware. iOS apps wouldn't be possible because they are native and use direct OS calls to do the job, while on Android you can port the middleware and just redo the connections with a new OS (and that can be already a gargantuan task).

Well, Blackberry did that with Android. But they did that on the same kind of devices that Android runs. Android relies that several tablet/phone specific hardware will be there to use, so it wouldn't work as it is. They would need to fork the Android middleware and change a lot of things. For a company with zero experience with full operating systems, it would be just a disaster.

Despite that, I'm highly sceptical of the interest that people have in apps on their TV. Apple TV success isn't related to millions of apps and Google's Android TV efforts have failed (and the new model is now based on a few key apps). What people want in the TV is only a handfull of apps with video related content (Netflix, YouTube, WWE Network, sports, etc). 

It will be their app store... They have control... They can just put the first party games first and followed by whatever hipster app gets popular on the casual mobile crowed. I mean, there are games on the wiiU for $2 but I doubt that gets that many sales and heck, if Parents buys a wiiU just to get even $1 games, I think Nintendo would be happy, all they need to do is charge a royalty on a per sale baises and just watch the money coming in...

Having Android apps on Nintendo hardware is the future. WiiU should have had this from the outset. Lack of multi-touch is an issue though.

No. And also no. Tablet games for an actual tablet cannot compare to legit, full blown games, even eShop games, let alone first party Nintendo retail games, on a video game console, with an actual game controller, that HAPPENS to have a fuckin' touch screen in it, among other extra features.

People really need to quit comparing Wii U's Gamepad to tablets. It's not. Not even close.