One trend that the author missed is that retailers are starting to use the Facebook Platform to enhance their own retail site. Companies like Amazon, Blue Nile, and Hallmark are using Facebook Connect to provide their customers with more personalized and social features. This approach makes the most sense since it allows retailers to focus their efforts on improving the experience of their own site, rather than investing time and money into a store that exists within the four walls of Facebook and fragments the online shopping experience.
My company Snapline (http://www.getsnapline.com) is helping retailers leverage their shoppers Facebook data to provide a better shopping experience on their retail site through features like personalized product recommendations and gift recommendations. I see these kinds of features becoming much more ubiquitous on retail sites in the next several years.