I'd say yes if Nintendo had been actually making efforts to persuade the "casuals" to upgrade. So far there's been little to no marketing, and no "Wii Sports 2" or any type of game like it to convince the audience who bought Wii to make the switch to Wii U.

I must agree - at least until the words are out - more games are out - and people can see the gamepad as  casual use

Seniors and mothers using tablets? Not gonna happen.

Yes but not necessarily forever. Nintendo just has to produce games/experiences that appeal to that group.

Currently they are VERY well served on tablets/smart phones so whatever experience Nintendo (or MS/Sony) comes out will MUST be something that can't be done on tablet's now.

This is the fundimental reason I say WiiU's gamepad is a mistake. Casual's don't want dual analog and already have lots of touch screens. The Wii-mote provides an experience tablets can't and Nintendo should have refined and enhanced that (with touch surface/screen sure) and continued to make great fun family friendly accessible to all ages Wii games for the casuals.

Wii Fit U is coming but will epically fail as no 'casual' is going to drop $350 (basic system + game - assuming they have a wii fit board) for a game that they already bought once or twice. Nintendo would REALLY have to show it's a vast improvement over the previous entries. It's not by all available info so far. Besides the exer-gaming fad is pretty much dead now.

A Wii Sports U would do better but still the use of the gamepad (and cost of the system) will discourage purchases. Plus what new sports would they do or what would be significantly better now because of the gamepad?

Despite all the failings of WiiU conceptually, a couple of major break-out hits (a guitar Hero or Just Dance if not Wii Sports) could revive it to healthy sales - IF it's not available on PS3/360 (which they would be if 3rd party)

It's simple. The casuals are already happy with what they have. They see no reason to upgrade, especially at that price.
Sony and MS aren't in such a bad spot because core gamers are insatiable for better graphics and sequels, though kinect 2 is going to have the same problem wiiU is having.

I think if Kinect 2 delivers on all the promises this time around and delivers a smooth experience like the leapmotion, just with your full body, then that will be able to wow people/ casual gamers.

Smartphones and tablets. Casuals want quick, cheap and easy games. An Android/iOS games costs US$ 0.99. 

There is a big difference in playing a game in a friends house for free and spending US$ 300 in gaming machines. People will already buy tablets and smartphones, so consoles will demand an extra money. The core business pay for it (and pays a lot if needed), the casuals have other things to expend money.

yes, but they are instantly able to drop $600+ on any gadget that "wow"s them

 Of course. But that is a phone. Everybody needs a cell phone. And people like to buy things that they can show to their friends. Talking about non-geek people, a Galaxy S3 or iPhone is like expensive clothes, it creates a status. A console can't do it. In the list of priorities for casuals, tablets and smartphones are ahead of consoles. And these two things are pretty expensive and you have to buy a new one in less than 2 years if you still want to have the "wow" device, so they keep demanding a money that could be for consoles.