I have a client with a publishing site. They want to add News and Events to the site. Would you create another document library with a content type derived from Pages? Or would you enable the collaboration features and customize the display forms of Announcements/Events?
I would enable the collaboration features. The reason is that it also enables the correct content types and everything became easily available in the content query webpart for aggregation. This eliminated the need for development customizations and it did fit with customer requirements. So in this case no development is needed.
If you go the route of pages and publishing then you will need to develop a custom content type and page layout so if I had no special requirements I would opt to activate the collaboration features.
My gut would say the latter. We typically have all collaboration based sites and enable the publishing infrastructure on site collections so that's what I'm used to. Some of the WCM folks might have other opinions.