WordPress is simple. If you are just going to be writing articles, making news posts, and adding a couple pages you could probably get by with using it.
Otherwise you are going to have to use a more advanced CMD. Mambo is pretty nice, but I'm not sure how well the development of it is going to progress since the dev team quit Mambo and started Joomla (
http://www.joomla.com/).
Another one that is really advanced and IMHO has a better skinning system and an easier plugin system is Drupal. Maybe large sites such as spreadfirefox.com and thisweekintech.com use Drupal, it is really scalable.
Of course if you want to be old school you could always just put up a copy of PHP/Post Nuke
Its really just personal preference and what you are comfortable with.
Cheers