You're mixing metaphors as articles are articles, so whether they are posted on a blog or a directory is kind of meaningless IMO. They are both technically websites no matter what you want to call them. Your content attracts readers, not software, if you have something valuable they'll keep coming back to read it no matter what the medium.
My directory has an RSS feed with many subscribers so I would say that anything with an RSS feed that helps people keep informed with their RSS reader will perform well.
Wordpress? Do you want to run a website or update blog software all the time? Do yourself a favor and try something that doesn't have a thread about it being hacked every other day.
[edited by: incrediBILL at 1:52 am (utc) on May 11, 2008]