New MacBook Pro Retina Hard Drive Type
The flash modules and controller of the SSD are blades (think naked SSD). They are not up to 3rd party configuration (at this time), but according to bmike, they are not soldered onto the main board and are actually discrete components.

However, there is no information as to what kind of proprietary (if any) configuration the blades come in, or whether they require an additional proprietary onboard controller (this may be likely given Apple's tendency to create speciality hardware for their line-up). So it most likely isn't the case that one could just crack open an existing SSD and use the blades within. A manufacturer would have to specifically design a unit for the new notebook. This isn't unlikely, but price will be the determining factor as it will be a speciality component.

It is also not clear at this time if Apple will make the components upgradeable, which is also a distinct possibility given how quickly SSDs are saturating the market place.

At best, it's a tentative "maybe."



You can read more about the new machine here: http://www.apple.com/macbook-pro/design/