Not wanting to be left completely behind, Yahoo will soon launch their own real time search engine too. But unlike Microsoft and Google, they won’t be partnering with Twitter and Facebook directly for the data (perhaps memories of their ill-fated blog search engine from 2005 linger). They’ll work with one of the existing real time search engines – that partner is OneRiot.
http://www.techcrunch.com/2009/10/27/yahoo-to-launch-real-time-search-too/