This article says nothing you don't already know, but it's worth noting how it's the payoff for a classic marketing department PR strategy: keep conducting "surveys" of some sort and publishing the results in press releases, and eventually someone in the trade press will cite them to write a trend story.
What we need is some nonprofit or government maintained list of viruses/Trojans From which all virus scan companies report to draw from and some form of at least basic detection Incorporated into every computer, as opposed to each virus scanner using it's own definition list. I mean this could be an issue of national security.