While I would absolutely love it if they could make this happen, I don't think it ever would. Sony and Nintendo tried working together in the past to create a CD add-on for the Super Nintendo (similar to the Sega CD only far better). The team up fell apart, Sony took what they learned and released the Playstation, which dealt Nintendo a serious blow when they decided to stick with cartridges for the N64. Nintendo also tried teaming up Philips to do the same thing, and that team also fell apart leading to the CD-i and the infamous Hotel Mario and Unholy Triforce.
So yeah, while I would love to have Sony and Nintendo exclusives all on one system, Nintendo has been burned enough in the past that I don't think it will happen.
They say, "Evil prevails when good men fail to act." What they ought to say is, "Evil prevails."
