My limited experience is that the admin / contributor interface matters for people who are meant to contribute and are put off by unfamiliar or confusing interfaces.
A few years ago I installed Drupal with the intent that secretaries would add items to its calendar. This didn't work nearly as well as wordpress with some refinement and a plugin that hooked blog posts into phpicalendar. Interface matters if he expects people internally who aren't bloggers to use it.
Nicely done, it's very clean.