WordPress rocks because it follows web standards, has plugins to optimize everything from title to content to IBL and OBL and no-follow, etc. Everything you need for SEO, you can do with WordPress.
At the end of the day, WordPress is not going to write your content for you :-). So that's still something you gotta do, but from a presentation and management perspective, WordPress is probably the best tool out there for creating content optimized for SEO.
Like Google warns, write your content for people and not for search engines. Do that and you'll be fine.