In his Youtube channel Joe Canti has shared few interesting videos presenting a quick overview of Flo and Us, a site built with Drupal 7, using Drupal Commerce for the shop and Panels + Panels Everywhere to theme the site.
It's not a complete tutorial - just a quick overview showing a little about how the two systems can work together.
Videos are available here: part 1, part 2, part 3 and part 4.
Some extra configuration information could also be found in Product integration with Panels? issue, where Kris Vanderwater explains how to add a relationship to the product entity via product reference field to have a Commerce Product entity section in the content_type selector, and thus all the product fields available.
If you have built a Drupal Commerce-based shop using Panels yourself, I would love to hear about your experiences! Please share them in the comments, especially if you decided to ditch product display nodes completely, and use only panel-based approach for presentation level.