Ever since ListActivatableNames() was added, it has included "org.freedesktop.DBus" as an activatable name:

commit 7628b541258d906e27e2000a402ed2d02383479c
Author: John (J5) Palmieri <johnp@redhat.com>
Date:   2006-07-14 01:17:59 +0000

    * bus/activation.[ch] (bus_activation_list_services): new function to
      get the list of services that can be activated
...
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2006-07-13  Carlos Garcia Campos  <carlosgc@gnome.org>
+
+       * bus/activation.[ch] (bus_activation_list_services): new function to 
+       get the list of services that can be activated
...
--- a/bus/driver.c
+++ b/bus/driver.c
...
+    /* Include the bus driver in the list */
+    const char *v_STRING = DBUS_SERVICE_DBUS;
+    if (!dbus_message_iter_append_basic (&sub, DBUS_TYPE_STRING,
+                                        &v_STRING))
+      {
+       dbus_free_string_array (services);
+       dbus_message_unref (reply);
+       BUS_SET_OOM (error);
+       return FALSE;
+      }

This doesn't make a whole lot of sense to me: by calling ListActivatableNames() successfully, you've proved that o.fd.DBus exists, which means it's irrelevant whether it is activatable or not.

Does anyone know why it gets returned here? I think it would make sense in ListNames(), but not in ListActivatableNames().