Hi,
There will also be updated documentation regarding this feature. Instead of using the “Create Rig” method, there is already a default Rig for Humanoids that you can use by enabling “Engine Content” from the Content Browser View Option. With that enabled, you should be able to select that Rig for use with Human characters you want to re-target animations between.
And yes, this is part of the 4.5 release.
-W