The big news in search this week was the announcement of Facebook’s Graph Search. But today, Microsoft is making enhancements to its own “social search” capability. Specifically, Bing is adding more content to its Social Sidebar feature.

In a way, this is a reintroduction of Social Sidebar following the news of Facebook’s Graph Search.

People will now be able to see considerably more Facebook data surface in Social Sidebar. This will include Facebook status updates, comments and shared links in addition to the Facebook content already present (i.e., Likes, photos, etc.). Microsoft said that people will now be able to see/search “around five times more content from their Facebook friends than before.”

There’s social content from other sources (Klout, Quora, Foursquare Tips, Google+), beyond Facebook, in Social Sidebar as well. But Facebook is probably the most important single source. After users link their Facebook accounts to Bing (sign in with Facebook), they automatically see status updates, images and so on that are relevant to the query entered into Bing.

It’s not clear how much usage Social Sidebar is getting or whether people see it as a differentiator vs. Google. Microsoft has continued to refine and enhance the feature, adding new content sources and capabilities. That suggests Microsoft still sees it as a worthwhile initiative and we can probably infer that there’s at least some traction there.

It will be interesting to see how the roll out of Facebook Graph Search impacts social search on Bing and whether there’s some “synergy” and increased usage, or whether Facebook search makes people less interested in social search on Bing. My guess is that social search on Facebook will be helpful to Bing and Social Sidebar usage.