Based on the sales of the WiiU/PS4/XBox One, I think that all three are going to fail!
WiiU
The WiiU will be lucky to achieve 20-25 million sales lifetime. Is it beause the system is bad? Yes and No. Yes, because the unique controller increases the cost of the system and the common folk don't care about it. Also, the advertising and messaging about WiiU has never landed that it is a SIGNIFICANT jump in quality from the original Wii. The No part is related to the fact that it has awesome first party support(finally) that can't be rivaled for years by the other two systems.
PS4
The PS4 has had clearly the best start and the best gaming powerhouse design of all three systems. Without much debate, the PS4 will probably outsell the WiiU and XB1 combined in the first 12-18 months. That is the real problem with the PS4. Past the intial rush of core gamers looking to upgrade their old PS3/360, the PS4 doesn't do much for the casual crowd. Also, the whizbang/shock of the graphics power(compared to the last Gen) will wear off quickly, as all 3 systems are truely underpowered at launch and will only get worse. The initial success(power/price) of the PS4 is it's actual long term failure. What does the PS4 have that people outside the core gaming community really want? Nothing YET... PS4 will sell 50-60 million MAX, probably closer to 50 million.
Xbox One
The Xbox One obviously has a few problems to overcome upfront. Microsoft failed on messaging when announcing the console and then failed with the price too. But did Microsoft fail on pricing? They did if they wanted to grab casuals from the word go, but not long term. Microsoft has planned the XB1's launch as a long term thing. Get the early adopters at a higher cost, because they will pay. Drop the price later as content and multiple(win8/winphone/XB1) platform delivery is realized. It has been reported that Microsoft is planning to make the windows phone OS free to cell phone makers. Microsoft realizes that long term, it's the ecosystem that matters and not the hardware. It's really only a matter of time before they drop the XB1's price below cost to gain maximum platform delivery. Even though most people don't want me to use the K word, I will say it. The Kinect is what will actually save the XB1 long term. The capabilities of the Kinect along with the XB1's HDMI pass through will be the systems big draw down the line. The Kinect/Multimedia capability is what makes it have the functions that help it cross over to the casual crowd. Unless Microsoft pulls the original Wii out of the hat and has a monster cultural craze to buy the XB1, it will probably sell the same 50-50 million as the PS4. The difference is that the XB1 will be more succesful in years 3-6.
So, how does this indicate that the Next Gen is a failure?
Like anything, it's all in the eyes of the beholder. Last Gen will have sold 270+ million. Based on my thoughts, this gen will sell 150 million at best. It's not because the products themselves are bad. It has a lot to do with things outside of console gaming. Smartphones/tablets/PC's/ the internet. I could get into a long debate on how those things will really be the demise of console gamings dominance, but that is another thread...
EDIT : Added Thoughts about the large #'s here at launch
The big launch numbers are expected based on the way people do preorders nowadays. Also, people no longer want to wait to get what they want, they go get it right now. We also had last gen systems that should have been replaced 2 years ago based on the hardware alone. All of this created a pent up demand that in previous genreations took the manufactureers months to produce. These launch numbers are big because Sony and Microsoft did an awesome job on production.
As far as the total console #'s being low on my estimates becasue of casual gamers. I think there are a bunch of gamers who buy COD and Battlefield and a sports game every year and that's it. Because the last gen systems have sold sos many and continue to sell so many, they will be supported really well for 2-3 years more. So, most of those titles will not require the casual crowd to upgrade to play. Sure, some will, but a good chunk will not need to right away.
It is near the end of the end....
