Supporting this would require a new iTween action. You do get a visual path editor with the iTween Move To action; you can use either nodes in the scene or Vector3 positions to define the path.
However it would be really nice to be able to build the path separately...
I'll make a custom action for this. Basically an iTween action that lets you pick a path name, like in the video. I can't include it in the official release because it requires the iTween Visual Path addon, but I'll make it available on this forum.
Thanks for bringing this up - I'd forgotten about the iTween Visual Path addon!