The video is quite old, from the January 6th, 2011 Friday New Product post. In that post it was announced that they would start carrying it soon, but didn’t have it in yet.
The next New Product Post, the January 15th, 2011 Saturday (because Free Day interfered!) New Product post does mention the product, and has the link. However, the product (COM-10202), has been retired and they will not be getting any more of them as they never quite intended to actually get them with the wallwart included :)
Even if there’s an inverter out there that ‘just’ plugs into the wall, I’m not sure that’s actually preferable – unless you have a particular use application where you can’t have any barrel jacks – since the separate adapter means you can replace that separately, shop around, etc.