Technorati's David Sifry released a new update on the blogosphere numbers. The search engine tracks 50M blogs, the number of blogs in its index doubles every 6.5 months, with 175,000 new blogs created every day.
Sifry claims Technorati has been able to weed out most of the splogging activity, but 8 percent of splogs do end up in the index. There's no word on how many abandonded blogs are in the index, or how many of the blogs are built exclusive on the RSS feeds of others without any original contribution from the blog owner (like this experiment of mine, both automated and abandoned). Blogs created by MySpace users are apparently not included in the index.
If you have missed it, here's a recent study of bloggers by Pew Internet & American Life Project.