Wordpress is probably the most well known, and most popular blogging platforms in the world today. There are millions of blogs that currently use Wordpress for their website. Wordpress has come a long way since it's creation, and also has a large development community behind it. There are more plugins being created these days that are taking Wordpress to the next level, and actually making it more of a CMS in the traditional sense. Out of the box, it is still just a powerful blogging platform, but with a few good plugins, you can have yourself an E-commerce store, a solid forum, or a community driven website like Reddit, Flicker, or Reddit. I wouldn't say it is as powerful as Drupal, but it is a quite a bit more user friendly at this point.