Security is more important than performance (finally)
Andrew S. Tanenbaum, Jorrit N. Herder, and Herbert Bos: Can We Make Operating Systems Reliable and Secure? (via /.)
You may recognize the name Andrew Tanenbaum, he disagrees strongly with Linus Torvalds (creator of Linux) about operating system kernel design. Specifically, he advocates microkernel-based operating systems, while Linux uses the traditional (and as we're finding out with modern operating systems, troublesome) monolithic kernel design.
I found all of the proposed designs very interesting. One of them comes from Microsoft Research, which I think is great news. It's too bad Windows is such an immovable force it will take a decade or two to make fundamental changes to Microsoft's core OS, but at least the effort has begun.