It would be great if the Xenforo core included a Social Group feature. Social Groups can allow for private forums, events, media sharing, and provide a great way to interact on a more personal level. The feature is included in the core for some other Forum Distributions, such as VBulletin. I would love to see it here as well. Perhaps it could be treated like Resource Manager, XenMedia, or the other official addons. There are several third party versions, but I would like to see an official, fully integrated and optimized add-on or core upgrade.