I don't for a moment believe that Nintendo felt the Wii U was a blue ocean product. Really, they would have to fundamentally misunderstand the concept of blue ocean to assume it was. I think they created the Wii U as a bridge to something else in the future and wanted to monetize it early, rather than wait for technology to reach a point where they could put all this together into a hybrid and not charge people an arm and a leg for it. In addition, I feel this strategy was an alternative to blue ocean... mostly because they couldn't find a new one. It's not that Nintendo didn't want another blue ocean product. They just had no idea what that product would be and they weren't sure if bringing out a sustaining innovation to the Wii [as in the 'Wii 2' I mentioned earlier] would really work. So they went with long-term initiatives, such as the alleged hybrid console/handheld.
That's my guess anyway.