No longer delete old feature service, now overwrite existing one
No longer delete old feature service, now overwrite existing one

The July 2014 update of ArcGIS.com added the ability to overwrite an existing feature service. The publish function was updated and the delete code removed. The script will maintain the original itemID of the feature service, thus webmaps will continue to work.
khibma/update-hosted-feature-service,arcpy/update-hosted-feature-service