These days the whole world is abuzz with the Model, View, Controller (MVC) architecture. This is not something new and is known by computer scientists for close to 30 years. I guess the new found popularity is due to the fact that this has heavy application is web development and lot of main-stream web development platform are putting in support for this. Ruby-on-rails and ASP.NET MVC are classic examples.
Coding horror has a nice post on this topic. I liked the following statement it made
"Skinnability cuts to the very heart of the MVC pattern. If your app isn’t "skinnable", that means you’ve probably gotten your model’s chocolate in your view’s peanut butter, quite by accident."
I actually use a very similar concept. The moment I see an application’s architecture (be it an interview candidate or a friend showing off something) I ask the question "Can you write a console version of this easily?". If the answer is no or it needs a re-design it means that the separation of model, view and controller is not correct. You are going to have a nightmare if you write and maintain that software.