The point is sort of that they're taking ideas from languages like Java and actually using them for OS/system code. You're right, it's all old hat for programming languages, but using it for the OS itself (usually done in C or assembler) is quite unusual.
Exactly. Dig deep enough in any modern OS and you'll find a heritage that dates back to the 60s. Since then we've come a long way. Byte-code VMs, advanced garbage collection, rich and robust interoperability between modules and services (JARs, .NET assemblies, WSDL, etc, etc.) But all of this is layered on top of the OS, which still has very primitive foundations.
Shockingly, there's been very little research in operating system fundamentals. One of the most important OS breakthroughs in the past 20 years was little more than an open source re-implementation of POSIX UNIX (linux), but very little has been done in terms of honest to goodness green field OS development.
I suspect we're not quite "there" yet in terms of having all of the tools and techniques available to finally justify kicking over the old OS foundations and starting anew. I'm certain that byte-code VMs (perhaps even LLVM itself), high-level interop, and garbage collection will play a big role. I suspect that some of the hot new (or rejuvenated) trends in computing especially functional languages, immutable data based programming, noSQL data stores, and especially event-based systems will be key parts in the foundations of the next re-invention of operating systems.
So it's at least an interesting experiment.