Easy and quick software update to the WiiU -> remove the mandatory and pointless gamepad -> sell WiiU w/o gamepad for 200$ -> sell infinite digits of WiiUs -> third parties will release exclusive games to a console that's more profitable (lowers graphics -> lowers assets -> lower cost)
Incidentally, improve online services and release GBA games in the Virtual Console; remove the Nintendo Club - NNID - Friend Code - Mii bullshit and propose a unified account like everyone else successfully does: people who actively play videogames, a.k.a. the only real target for any console business that wants to be sustainable year over year, are smarter than Nintendo.
Remove region lock, actually listen to gamers like Sony and Microsoft did.
In short, Nintendo has super easy choices in front of it, but they're stubborn, archaic, close minded and control freaks.
Removing the GamePad would not be an "easy fix".
Also, Nintendo Network is technically a unified account now. Miis aren't "bullshit" and friend codes are gone, though they cannot be removed from the 3DS. eShop purchases are now linked to it somewhat too as evidenced by seeing eShop activity for both 3DS and Wii U in both 3DS and Wii U now. They just need to make a way for you to unlink it with one console and link it with another so that your purchases can carry over. Other than that, it is unified, it is a single account. So how, pray tell, is their NNID account system "bullshit" and needing to be removed? By complaining about NNIDs and Miis, and even Club Nintendo, it gives the impression that you don't actually know what they are.
As for region lock, would it be nice to remove it? Sure. Would it actually make a difference? No. Region locking only matters to a very small, yet very vocal, portion of gamers.
Also, the Wii U being cheaper, without anything to differentiate itself from others, in no way guarantees sales. In fact, I argue that it'd make the situation worse.