I've spent many hours examining documents that Microsoft had produced about its Midori OS incubation project, and became very familiar with its concepts. Over time I've seen several Midori ideas implemented in .NET: a more efficient runtime (Silverlight), its programming model (F#), and began to think of Windows Azure as a potential vehicle for delivery. Google has developed new legacy-free techonlogies for dealing with distributed concurrency such as "Go," which breaks from C/C++. Microsoft could up the ante with Midori.
That said, I'm not certain about the project's current status. The company is working on other projects to deal with concurrency at the OS level, and I've been told by insiders that it has many incubations in the works. Midori was differentiated from those, because Microsoft placed the project under the jurisdiction of executive Eric Rudder and began recruiting allstar programmers to the project. Either way, it has determined that it cannot tackle the challengies of concurrency (devices, cloud, on premise, many-core) by evolving its existing technoolgies.