I myself use the MVC pattern. I am not sure if the simpler model you describe is really
easier than MVC? Maybe I am missing something?
To answer your question: yes, I think how you describe it is ok. (I never heard about the
"controller" pattern, so I might be wrong).
However, I would advice you to use MVC. The only difference is the following:
The "Core Logic" updates the "Controller" & then the "Controller" updates the "GUI".
In MVC, the "Core Logic" directly updates the "GUI".
I don't quite see why the "Core Logic" has to update the "Controller", it's one more method
you will need to implement which does not do anything more than just update the "GUI".
MVC would be shorter in that case.
Also, look at the diagrams, MVC and your pattern are pretty much the same:http://www.enode.com/x/markup/tutorial/mvc.html