Twitter @bitcointalk is official, but I only use it for outage notices and such. If there are no problems, then there will be no @bitcointalk messages.

I don't use social media. If you think that some social media functionality would be useful (such as pointing to interesting posts), feel free to do it yourself. If it's an interesting project, I might be willing to create APIs to help you. But since I don't use these sites, I don't even know what people would want.