The guys from The Tech Report discovered a patent application from Microsoft for some sort of modular gaming system:
A gaming system including handheld devices and console devices has variable functionality and processing performance as determined by the number of components in the system. Gaming components can be combined wirelessly, by wired connections (e.g., via a docking station), or a combination thereof. The processing capabilities and functionality of each gaming component in a combination are augmented by the processing capabilities and functionality of other gaming components in the combination.
To take advantage of another gaming components processing capabilities and memory capacity, each gaming component is capable of utilizing another gaming component to process gaming applications. Further, each gaming component is capable of rendering audio and/or video information provided by another gaming component. Also, a gaming component is capable of utilizing another gaming component as an adjunct processor.