Slackware is king!
At the recent KDE 4.0 Release Event in Mountain View, California, members of the open source community at large were invited to attend to partake in the celebrations surrounding KDE 4.0.0's release. There were many attendees from around the world, but the real surprise came when we counted those that were representing the distros.
You see, Slackware accounted for half of all the distro people at the event. Since this event was fairly well attended, one can safely assume that this ratio is actually an accurate representation on reality, and that Slackware is once again rising to reign supreme as the most popular linux distro currently being produced.