Example Sites

I discovered Multiply.com after reading about it in InfoWorld. The editing panel was shown in an picture. It looks pretty straightforward, which is nice, and helps me start to sort out the big initial question: How do I model the data on the site?

For example, any of the following entities might be subject to editing:

News Articles
Interviews
Blog Posts
Picture Libraries
Book Reviews
Journal /Magazine Details
Events

This is a pretty broad group. Normally, in days past, I would have modelled all these separately. I wonder if it doesn't make more sense to try to meta-model all of the common elements (if possible), which might make the system more testable and extensible.