In addition to the Sony E-mount roadmap from yesterday, there is also a new Ricoh GXR roadmap. The big news here is that in 2011 Ricoh will also offer expansion units but the roadmap does not specify what mounts will be supported. Previous rumors already suggested MicroFourThirds module and even Leica M mount and Hasselblad mount prototypes were floating around few months ago.
You can see all currently available GXR products and prices on Amazon.