Alfresco, at its core, is a general purpose content repository with content management services. There is an application surface, the web client, , which at the moment is very document-centric. However, this will be changing this year, with WCM features arriving from about June onwards. There are features already there that people are using for managing content that is served to websites (e.g. transformations, content templates), but capabilities like site management are not there today.
Watch out for announcements next month about our WCM 🙂
Cheers
Paul.