Basically they're turning Steam recommendations into reviews that people can vote up or down. I'm not a fan of the idea, personally. Given how awful the Steam Forums are, I'm really not interested in having reviews from random people cluttering up store pages, and the voting system will inevitably lead to reviews getting voted down for disagreeing with whatever the popular opinion is.
I wish Valve would start focusing on more important things, like making DLC installation separate from game installation and giving users more customization options for the client. The Library in particular could benefit from new sorting options and things like that.
I think it sounds fun. Gonna a do a few joke reviews (as in it won't really be helpful at all) and see how it goes. Already got a rough draft of an Arkham Asylum review done, not posting it yet though.