This product has since come out. In this entry, I described what the guides would allow you to do so there actually isn't one in the video, but I wanted to make people aware that they were coming out with some information in case they wanted to pre-order.
I have a review article and video on the Self-Centering Guide SCG-10 here.
So... the rest of this is for posterity... :)
Rick Christopherson is soon releasing to manufacturing a Domino Self-Centering Guide (SCG-10). Many people have asked me about the narrow-stock spacers I use on my pin Domino, but these only work for the older pin-style Domino. Rick's new Domino accessory looks to be an infinitely variable version of those spacers that can use the entire width of the Domino. This looks very promising to be the answer to the narrow-stock spacers for paddle-style Dominos and an improved version for pin-style users.
This video discusses what it is and how it works. He is releasing it to manufacture very soon and starting a pre-order list. I want you to know about it in case you are interested as this isn't a product that will get much publicity except through word-of-mouth.
Information on the SCG-10 will be posted on his accessory site: DominoGuide.com. Currently it only discusses some multi-stop accessories that are already out (and that you might like as well). If you have specific questions about the product, its availability, or even being put on a pre-order list, send him an email at: sales@DominoGuide.com.
I have no affiliation with Rick Christopherson; I just see this as a very nice addition to the Domino my blog readers might like.
There's a nice thread on talkFestool about it here.