NEC has been a partner with Nintendo for a while now especially making there chips. That's how Nintendo avoid the problems that nVidia and Microsoft ran into. Not to mention that NEC has one or two complete factories working exclusivly on Nintendo's chips for their systems. They are currently stamping the GPU and the MoSys memory onto the chips.
But as for the central processor there are plenty of other sources, they could go with NEC, but they could also go with Motorola which made the GBA's processor. Then their is AMD, or they can set out of get new talent like they did with MoSys.
As for the disc they wouldn't go with Blu-Ray for obvious reasons. They may deepen their partnership with Panasonic and maybe score a hybrid of the new disc they came up with. But truely DVD should stay the standard until the developers start to figure out how to fill over one DVD because the excess money it costs for these new formats will be pointless if the developers can't fill them in the time frame they have to get games out to be viable. Because there is only so much code you can do in a set period of time and developement cycles are being pushed into a shorter time frame for the third party developers. Personally I kind of like the idea of putting the disc in a tray with a flash chip in it that could elimate the need for memory cards. (Like SD technology.

)
Note: You moved this as I was writting this. I kind of made my heart jump seeing it disappear.