http://www.eweek.com/article2/0,1895,1863526,00.asp
"We've built an operating system written entirely in C#, all safe code except the kernel and a HAL on top."
http://channel9.msdn.com/ShowPost.aspx?PostID=68302
"This isn't the CLR. In our world, we compile entire MSIL for the kernel into x86 instructions at installation time. There is no libc at the bottom.
However, we do have around some assembly code. Like a kernel written in C, our C# kernel needs assembly code to handle the lowest part of the interrupt dispatch on the x86. But once the assembly code has finished, it dispatches directly into compiled C# (no C). BTW, there is some C code in the system, primarily for the debugger stub."
Osea, casi, pero no todo en .NET, imposible.
http://research.microsoft.com/os/singularity/
Mi opinion: no lo veremos, si es que en algun momento llega a buen puerto, en los proximos diez (cinco siendo generoso) años. Especialmente teniendo en cuenta que todavia no salio vista, la version 6.0 de NT y esto implica una ruptura total con el pasado y el soporte hacia atras. Lamentablemente esa parece ser la tendencia.
http://www.joelonsoftware.com/articles/APIWar.html