But there's nothing wrong with the idea of using Linux as a desktop OS; I've been doing it for years and it is in fact the stated goal of the Ubuntu distribution, among others. Linux is still deficient as a general-purpose OS for end users in some ways, and Cyan has raised a useful topic for discussion, even if I don't think he's really explained what Mint does that standard Ubuntu doesn't.
As for me, I just upgraded to Karmic. I THINK KDE 4 has finally risen to my standards, but I'm sure I'll have a lengthy, bulleted list of everything wrong with it if it still hasn't. (EG: I seem to have broken the rather neat Expose-style alt-tab configuration I was using. That's not really make-or-break, as I can always just go back to the old-style list version. Which is what I'd be doing in KDE3 anyway. Also, the program that's supposed to report crashes keeps crashing.)
fglrx (the proprietary ATI video driver) still appears to suck. I'm getting a lot of tearing with any kind of OpenGL stuff.