I wonder if ror is really based on MVC though they claim, otherwise I am probably ignoring something very obvious.
Refer to the Wikipedia article http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller
Look at the diagram there. In ror the views dont refer Models directly. Its done essentially through the controller isn't it ?
Check out his component diagram http://lh4.ggpht.com/Dikiwinky/RwGSHOH-OWI/AAAAAAAAAEI/4UH_4ohjC4U/Rails2.png
Here also there is no interaction between Model and Views.
From this RoR appears to be just a 3 tier architecture.