Although probably another fake, it's the first one with some logic behind it. Nintendo already said their next handheld and home console will have the same architeture. The most possible outcome is that the sucessors for Wii U and 3ds have around 30-40% of it's first party lineups as major exclusives, with the rest (major multiplayer titles, smaller 3d games, all 2d games) getting the smash for Wii U and 3ds treatment. The visual difference would be smaller due to the power gap shrinking and there should be cross buy and cross local/online multiplayer for shared titles. Same cross buy for virtual console titles.
Sharing the whole library is not only impossible but also a terrible business decision. That's because exclusives are what value a platform.
