Please no. The Wii U is in dire need of something extraordinary from these guys.

Retro has been hiring a lot of people lately (they even bought a new building), so it wouldn't surprise me if they are working on multiple projects. This is their new place btw, from the outside it looks really big.

They probably are working on Mario Kart, but im sure that's not the only thing they're working on.  Btw I actually thought the Metroid/Star Fox game sounded cool

I for sure do not want them to be working on MK7.

However, I am severely divided on what I want to see from them.

Do I want Metroid HD with badass Samus? Or do I want a new stunning IP?

Wouldn't surprise me. I doubt the Japanese suits will let them work on some big new unproven IP. The Nintendo that would allow that died a long time ago (go read the Howard Lincoln article). 

NCL uses a small handful of Western studios to work on existing Nintendo franchises they don't have time for basically and that's it.

Or it could be that whatever Retro was working on has been put on hold and they've been assigned to help EAD on Mario Kart U, now that Nintendo is in "panic mode" as they've realized NSMBU and Nintendo Land aren't selling Wii Us like they thought and they need Mario Kart for Christmas to save their bacon.

GOD PLEASE, NO

It's possible they were yanked from whatever they working on (Star Fox?) to help EAD once again with Mario Kart, as getting Mario Kart out may be reaching emergency proportions for Nintendo given the horrid state of the Wii U right now. 

If Mario Kart is not done for Christmas, I think Nintendo has basically screwed the Wii U up entirely. Not even 3D Mario and Wind Waker are saving that train wreck. 

I want them to do a new IP, (obviously with nintendo overseeing them ofcourse). But yeah, Aside from liking Re5 a lot. I agree with Retro taking over the franchise from just helping last time would be disappointing.

Retro needs to optimize their knowledge about Wii U, they need to implement knew ideas to see which one is better. Nothing is better than doing it in other games.
Gamers also expect Nintendo to throw all their franchises in one year. That doesn't make any sense to me.
You already saw what Monolith is working on, what is the problem about letting Retro split in several teams to work on different Wii U games?
Remember Retro was in charge of 4 projects when hey were bought by Nintendo. None of them make the cut. Miyamoto step up and give them the spirit they needed. I am not saying they are bad, but they need to polish their experience with the Wii U.

Why is Nintendo putting an A team on a 3rd rate title like MK? Silly Nintendo.