rainborick - 9:35 pm on Aug 16, 2012 (gmt 0)
My guess is that the prevalence of left-hand navigation is partly thanks to the early days of the web when page design options and screen space were both far more limited. It's also certainly, in part, due to the fact that the web is dominated by left-to-right languages so users will naturally start to visually scan a page at the top-left corner. Even the fact that browser windows expand along the bottom and right-hand edges likely influences the inclination of designers to position the navigation menu along the left edge of the screen where it will tend to remain visible no matter the screen or browser window size.
But is the practice outdated? I don't think you can say that categorically since several of the factors I mentioned already are still applicable. But, as the saying goes, form follows function. For a visually-oriented or informal website, the design doesn't need to heavily favor such principles. There's another cliche' that fits well here: It's an art, not a science. Or: One size never fits all. I like them both.