Derived from #1033818: Move xmlrpc includes into xmlrpc.module, this issue is to track the removal of the XML-RPC API in Drupal. Since there is no Blog API in Drupal core anymore, there is nothing left in core that actually makes use of the XML-RPC library, meaning there's no reason to have it left in core.
It can easily live on at http://drupal.org/node/1285602 .