Trying to figure out the best way

I’ve got an issue regarding the whole blog idea and SEO and would like some other ideas/opinions beyond my own. I am looking for a way to set up a centrally-located, web-based blogging platform, whereby multiple bloggers can login to post articles, which they in turn are able to assign to a variety of websites (with different domains) – so that the assigned domain gets the full benefit of each individual post’s SEO value.

I’m pretty sure I can do this with wordpress.com if I pay 10 bucks a year per domain, and from what I’ve seen of wordpress.org 3.0 I should be able to setup multiple domains myself. I’ve also got some experience with Codeigniter and am interested in getting WP and CI to play nice.

I’m just wondering of anyone here has any ideas/thoughts on the subject they’d like to share!