Building CMS from the ground up

I've been looking at using WordPress when doing freelance web work, but honestly I'm looking more and more at just rolling our own CMS.  Doing this will allow us to better theme it plus I can integrate new content into a custom framework MUCH simpler then trying to learn the in's and out's of WordPress, Joomla, or other canned content management systems.

While at Hillcrest I built a from scratch CMS using ColdFusion around 2001, and it was used until about two years ago when they outsourced the site where the outsource company moved it to Joomla.  So with this plus working with WordPress and Joomla I'm confident I can build a pretty good CMS that meets our needs, but it'll take some time to build since I plan on taking full advantage of OOP and PHP for the framework plus jQuery and jQuery UI for the aesthetics and CKEditor for the actual page editing.