code: function() {
          
          if (this.map.baseLayer) {
              //dont need to listen for this one anymore
              this.map.events.unregister('changebaselayer', this, 
                                         this.setCenter);
              
              if (this.displayProjection) {
                  this.center.transform(this.displayProjection, 
                                        this.map.getProjectionObject()); 
              }      
  
              this.map.setCenter(this.center, this.zoom);
          }
      }
docs: Method: setCenter
  As soon as a baseLayer has been loaded, we center and zoom
  ...and remove the handler.