Privet: How to Shape It?

I obtained this privet from a group dig in the fall of 2007. It has been growing in a box ever since then, with a root trimming and trunk reduction in spring 2009. I am still trying to decide where to go with its shape.

Originally I thought I would get rid of the heavy central trunk entirely and allow the smaller side branch to become the leader. However, now I'm second-guessing that plan. I now wonder if I should keep at least a couple inches of this large central trunk to provide a more realistic taper from base to trunk.