It is definitely going to the front-end, especially for sites that want to benefit from user contribution. In this context, what do you think about Kinja ?

Kinja is our publishing platform designed to make great stories by breaking down the lines between the traditional roles of content creators and consumers. Everyone — editors, readers, marketers — have access to the same tools to engage in passionate discussion and reveal the truth. Sharing, recommending, and following within the Kinja ecosystem allows for improved information discovery.