@Kevinjohn Gallagher - I agree the "best in breed" comment is without merit, but most of the CMS requirements you listed here are covered by a number of high quality plugins (and that form of coverage is no different than how the Drupal or Joomla ecosystems work).

1. Document management — Check out Ben Balter's Google Summer of Code project. It's a fantastic piece of work.

2. Workflow management — See Edit Flow, already used in a number of newsrooms.

It's worth nothing that Document Revisions and Edit Flow interact with each other — have them both on the same site, and you can use the manage a workflow for your documents. It's mighty clever.

6. ESI Caching / CDN ability — W3 Total Cache supports the gist here.

7. WYSIWYG editing — Despite the bad rap given to most WYSIWYG editors, MoxieCode's TinyMCE is the best one out there. Core supports it out of the box of course, and plugins and themes are pushing its limits with the editor API and editor styles.

8. Single Sign-on — With what? There's plugins to do this with social networks, specialized authentication systems, and the like, and building a plugin for a system that isn't covered is easy.

9. Multi-side Admin — Ours is pretty good. Could be better. Have any ideas?

11. Access Management — Combine a plugin like Members with a plugin like Edit Flow, toss in some custom capability code, and you have yourself a pretty good base system.

13. Multi-lingual — This is definitely a sore spot. Most of the plugins that try to do this, do it really poorly. Not much different than the e-commerce offerings, currently.

I certainly didn't cover all of your points, and some of them have no corresponding WordPress solutions. Some of the plugins I mentioned are nascent. What we need is the demand to occur and the ecosystem to step it up. "If you build it, they will come" isn't really a core philosophy.