If you see a good UI walkthrough - you probably didn't notice it
blog.kera.io
blog.kera.io
http://www.youtube.com/watch?v=8FpigqfcvlM&feature=playe...
The article hit the nail on the head: the best walkthrough is the one that it nearly invisible to the end-user, yet still accomplishes its goal of progressively introducing a UI to them in a long-lasting way.