Nielson//NetRatings released a report:
6.6 percent of the U.S. adult online population, or 9.2 million Web users, have recently downloaded an audio podcast; 4.0 percent, or 5.6 million Web users, have recently downloaded a video podcast. These figures put the podcasting population on a par with those who publish blogs, 4.8 percent, and online daters, 3.9 percent.
Looks like podcasting has overtaken blogging as the next popular online activity? The full report goes here.