Microsoft Research has released our "concept car" or prototype of the operating-system-of-the-future. It is called Singularity. The operating system is available for use by academics.You can find it on Singularity on Codeplex site.

Singularity is designed to make it easier for researchers to test how operating systems and applications interact with each other.

Singularity is a research project focused on the construction of dependable systems.  Singularity uses type-safe languages and an abstract instruction set to enable what we call Software Isolated Processes (SIPs). SIPs provide the strong isolation guarantees of OS processes (isolated object space, separate GCs, separate runtimes) without the overhead of hardware-enforced protection domains.