At this point, I don't see how any of the three platforms can dominate ala NES, PS1, or PS2. The Wii U will lack the 3rd party support and the PS4 and NextBox will likely come out the gate at $500 or more. Furthermore, if what we saw at the PS4 reveal is any indicator, there won't be a huge gameplay leap similar to 3D platformers on the N64, open world games on the PS2, or online shooters on the 360. That will slow down the adoption rate for the Ps4/720 more than the Wii U, since at least the U will cost more similarly to the PS3 and 360 and while having years of support ahead of it.
Honestly, this generation could end up with the first notable contraction in console history, particularly since Sony can possibly die 2/3 of the way through the generation if things go sour. Add in the resurgence of PC gaming, competition from the mobile devices, and non-gaming machines being used for things like playing media, and the market could end up a bit crowded.
Here's how I can see the rest of 2013 and some of 2014 going down.
Wii U: Continues to do poorly until the holidays, when a couple of 3rd party games combine with the might of Wind Waker HD, Mario Kart, and the minor hits of all year to give it a solid Q4. 2014 will generally go well as the platform enjoys the best 3rd party support of its life, thanks to combined overlap with 7th gen and 8th gen machines (See Watch Dogs and Call of Duty), and games like 3D Mario, Project X, and Yarn Yoshi, come out. The Wii U will likely be the only 8th generation console that matters in Japan until 2015 or so, seeing as there's no reason the PS3 won't steal support from the PS4 like the PSP is stealing from the Vita.
PS4: This system will get off to a rough start. Sony has yet to reveal a real killer app for the system (No, Sci Fi CoD and multiplatform games don't count), so at this point, it looks like the system will start off without a really big title. Combined with the high price of entry (I'm sticking to $500 until proven otherwise) and the still decent costs of established machines (The PS360 will likely still cost $200 this holiday season), it will have a hard time getting established. This is made even worse by the lack of a revolutionary new media to push hardware. More than one person bought the PS2 as a DVD player and the PS3 as a BlueRay player. Seeing as how people can get Netflix on their aging Wii nowadays, it's likely that the PS4 will have to stand on its own.
NextBox: See the PS4, albeit slightly better off. Microsoft has inferior 1st parties to the other 2, but several things put them at an advantage. First, Kinect 2.0 ought to win over a few casuals, especially after making a big splash since 2010. Second, Microsoft will likely have a Halo game and some nice casual-oriented games available around launch, which will sell a lot. But the likely $500 price point will drive people away.
Conclusion: I'm not tooo optimistic about the 8th generation. I was a couple of months ago, when the PS4 had 4 GB of RAM. But after this week's presentation, it looks like the industry is going to go through some hard times.