Use of the Visitor pattern and possible over engineering

Question

I am developing a small application in .NET and am thinking of using XML to save the object model.

My first thought was to separate the model and the generation of XML by using the Visitor pattern. The class would walk the object hierarchy and create the XML. But then I thought about the Extreme Programming method and the "you ain't gonna need it" (YAGNI) principle.

I don't envisage needing to create another Visitor to output the data in some other way (it's a simple app) I just want to use a human readable format to save the application's data.

Should I use the Visitor pattern or am I just over engineering the solution?