Honestly, isn't Slashdot about news for Nerds and stuff that matters? So why do we keep discussing operating systems? The far more interesting stuff is built on top of the operating system, and the operating system merely serves that. I don't use the operating system to draw in 2D or 3D, I don't use it to write software, and I don't use operating system to write mail and posts.
Current operating systems offer file systems and hardware abstraction, and have done that for decades. We should be discussing where we want to take technology, not where it lead us in the past. How can we find better metaphors for storing data than a folder structure? How can we improve collaboration between different applications? How can we make more intelligent machines? Let's keep dreaming, and find ways to make these dreams come true.
This isn't to belittle the efforts of Linux, Microsoft or Apple, but just to put stuff into perspective. Operating systems are overrated. When people care about code being able to run on several operating systems, that just proves my point.