_loadChildrenFromWebService() is a good client-side way of 'pre-caching' downlevel menu items while its being expanded. I would like this method to have a fully supported, external method, so that it might be maintained in future releases (it was broken in Q3 2012 for Android browsers for instance).

Additionally, it would be useful to avoid round trips, if it could work from a set of RadMenuItems, so that several RadMenuItems could have their children populated in a single request to the server.