Trend: Businesslogic in Model

When you take a closer look at the new Application-Frameworks such as Ruby on Rails or JBoss Seam you will notice a change to previous architectures:

The domainmodel is no longer a pure datacontainer, but it contains the businesslogic as in the early years of OO.

For many datadriven applications there will be an advantage that you can ommit an unnecessairy layering. Thus the logic for one entity will be in this entity and you can avoid codeduplication. Your will be more DRY (don’t repeat yourself).

I’m wondering how you think about this trend and if anybody has allready implemented any bigger project in this meaning.