WordPress is first and foremost a blogging platform however over the years, it has graduated into a full fledged Content Management System (CMS) with a robust admin back-end and highly modular and extendable functionality. We have installed and used WordPress for several clients the last year or so and have had no complains yet.
The fact that we use WordPress as a CMS for clients doesn’t mean that the other options out there are poor choices. Just that WordPress is extremely easy to use (as opposed to, say, Joomla) for not so familiar clients and this comes very handy if the client intends to manage the CMS all by himself without an elaborate team. WordPress adds a solid support for “static” content, being the WordPress Pages, and more newsy update flows controlled by the Posts, and you’ve got your needs pretty much covered for most websites online today.