beSpacific: Gartner Releases 10 IT Predictions for 2007 and Beyond:

Among the predicitions, is the following - "Blogging and community contributors will peak in the first half of 2007. Given the trend in the average life span of a blogger and the current growth rate of blogs, there are already more than 200 million ex-bloggers. Consequently, the peak number of bloggers will be around 100 million at some point in the first half of 2007."