you may think my optimism for Wii U is funny, but at least I have well thought out reasons. When dealing with an issue this broad, there's obviously more factors than I have time to address, but some of the major ones include:
Nintendo has their restructuring in the rear view mirror, and are bigger than ever. More employees can mean bigger teams, bigger games, more teams, more publishing power, etc. I believe Retro now has 2 or 3 teams, Monolith has 2, and so forth. Wii U will see more Nintendo developed and published games than any of their past consoles, and many will rake in some money. Nintendo is already showing this by publishing the Platinum games, LEGO, Rayman, and partnering to make SMTxFE. It's a winning strategy.
the 3DS is on a roll and may be in for it's best year ever, especially with the world wide system seller Pokemon on the way. With 3rd parties having great success on the platform, Nintendo can turn their focus almost completely to Wii U.
barring contract type deals, Wii U will be the cheapest console from the big 3 on the market. This is hugely important and just like the Wii, is certainly no accident.
With Wii U Nintendo has more options than ever before. The most obvious of which is HD remakes/collections of GC and Wii games. These are all easy money and help fill out the release schedule. I wouldn't bet on Nintendo making the smart choice, but it's promising that they have the option to make Wind Waker HD just the start of a long line of exciting remakes. Look no further than the numerous HD collections on PS3 to see the sales potential. More easy money can be made now that Nintendo releases full games on the eshop.
Along the same lines, Nintendo has quite a few trump cards. An MMO-style Pokemon game on Wii U is the ultimate system seller. I also think games like Smash Bros and Zelda have room for growth now that they will be in HD and should sport better online capabilities than ever before, and the superior graphics will make TV spots and advertising more effective. There is also evidence that Retro's Wii U game is a Western focused game, and with their excellent track record they might have a 'Halo-killer' system seller releasing as early as this year.
Iwata has said blue ocean games are on the way. Now that the market has changed they might all be long shots, but with a track record like Nintendo's I wouldn't count out their ability to pull in casual and non gamers.
I don't rule out the possibility that the Gamepad could be a system seller. We won't know for sure until Nintendo launches a large advertising campaign in which they show off TVii and all the other neat apps and features. The fact half of NA still hasn't heard of the Wii U is viewed by some as a negative, but I'd argue that it gives the system future potential as more people are introduced to it.
I can predict one of the responses I might get, which is that much of my positivity for Wii U (to be a very profitable console) are based on maybes. It's a valid counter argument, but I think there are enough maybes, enough potential and possible home runs that I feel good about the U's future.