I was just playing around with the new WordPress 2.9 Release Candidate last night. Wait until that comes out then judge from there as it really is going to turn heads. It should be out by the end of the week from my source. As far as ease to use, Joomla is alot fo lears, customization in WordPress is much easier, but Joomla is much more powerful. I would just base it on how easy you want the site to be to use and update and go from there.
I think Wordpress is excellent. It's very easy to setup and the learning curve for posting to it is minute. You can set up a great SILO structure very easily - using pages or categories. I don't know what Joomla templates look like, but Wordpress has many, many free, beautiful templates - and there are more robust templates available for moderate costs. Plus Wordpress has many SEO beneficial plugins. The recent advancements in adding plugins (right from the back-end), updating plugins (1-click) and updating your Wordpress install itself (also 1-click) make Wordpress an excellent, easy CMS.
I know Joomla is a wonderful CMS which is getting famous by every passing day. Building a website through Joomla involves less time. Within the shortest span of time, we can build a wonderful website with excellent content management system.