Before the implosion, I heard one of these designs, 3 driver arrays in a single enclosure, from Elemental Designs. It sounded pretty good, but I was left wondering, if you're going to add the complexity of an AVR, why not just get 3 wall mountable speakers? The added cabinet volume by taking up the entire width of the bar does help frequency response, but 3 separates allow you flexibility and the ability to fine tune your stereo image.
In my opinion, one of the great things about soundbars is they relative simplicity of setup and lack of multiple components to house in your viewing area.
At any rate, there's plenty of case scenarios for self-powered soundbars, the soundbar-style passive speakers that you posted, and separate speakers. If you go the pasive bar route, and find one that you like, be sure to post and let us know.