1) I can customize it in a jiffy. Wordpress 2.0 has a hook for everything which I can plug into by adding add_filter(’some-hook’, ‘my-function’); to my code. For example, I could add a filter to fire before and after a comment is saved to say, count the hit/miss ratio of Akismet. And, basing everything off streams and filters is infinitely chainable in the future.

2) It’s fast. There’s now an object and query cache so that Wordpress doesn’t have to run to and from your MySQL database so often to render your frontpage. This, combined with the ability to write a caching plugin like Digg Defender or WP Cache, makes one able to scale Wordpress almost infinitely.

3) Themes. There are more themes for Wordpress than any other blog engine. There are literally thousands, from the famous Kubrick to the yet-unknown Elliottback theme.

4) Active. There’s going to be a free Wordpress 3.0 out in the near future, and it will continue to rock as much as it used to. Because development is active and ongoing, I remain committed to the platform.

If PHP isn’t for you, I hear Typo for Ruby on Rails is good.