I just stumbled upon Mark Simonson's "The scourge of Arial", which outlines the history of that incredibly ugly font.
Makes for interesting reading. It turns out Arial was developed as a "look-alike" font based on Helvetica, one of the more popular/trendy fonts of the mid to late 20th Century. Font vendors created Arial to compete with Adobe, which licensed Helvetica in the early '80s. (Yes, that's much like creating a generic version of Cheerios.) The result? A lousy-looking rip off of a font that, according to the article, was out of style anyway.
After reading the article, I wondered how many news sites used Arial heavily, and whether the use/avoidance of Arial correlated in any way with site quality. After a quick, unscientific glance at the list of 2002 EPpy Award winners, I reached my unfortunate answer: 13 of the 20 award-winning sites use Arial in some way on their home pages. (Yuck!) Six use Arial extensively for navigation. (Double yuck!) And here's the killer: The site that won the award for "Best Design of a Newspaper Online Service," usatoday.com, uses Arial to an almost pain-inducing degree.