Yesterday, Microsoft rolled out some deeper Facebook integration into its Bing search engine as a competitive differentiator versus Google. Today the build-your-own magazine app Flipboard gets blekko’s human editor-guided search engine for topical RSS feed searching. Is Google at risk from social-powered search? Perhaps, though I’m not a big believer in friend-recommended results for a lot of commerce, comparison, scientific or academic categories. Certainly, Google needs to incorporate social signals into its results ranking, and Microsoft has an easier path – through an explicit deal with Facebook – for achieving that. But be careful over-interpreting search market share data. Bing’s gains – incremental at best – seem to be coming mostly from its partner Yahoo’s losses.