As we speculated, Automattic, provider of the WordPress open-source blogging software and spam filter Akismet, has raised $29.5M in a Series B round of financing led by Polaris Ventures (which put in $20 million of the $29.5 million). Other participants in the round include The New York Times, True Ventures, and Radar Ventures.

The large injection of capital will not only go towards the development of Akismet and WordPress (the downloadable software) but the development of WordPress.com (its hosted blogging platform), Gravatar (its avatar offering), and BBPress (an upcoming hosted bulletin board product) as well.

WordPress.com recently boosted its storage cap to 3GB, far surpassing its competitors Blogger and TypePad. WordPress was honored twice at this past week’s Crunchies in the categories of “Most Likely to Succeed” and “Best CEO”.

Last October, Automattic was rumored to have turned down a $200M acquisition offer. The question is: how much did the founders take off the table with this round?