Yahoo will be closing down Yahoo Site Explorer this year. Yahoo has just announced
the date for the closure. This coming Monday, November 21, 2011, Site Explorer will cease to exist. The short Yahoo blog post reads:
With the completion of algorithmic transition to Bing, Yahoo! Search has merged Site Explorer into Bing Webmaster Tools. Webmasters should now be using the Bing Webmaster Tools to ensure that their websites continue to get high quality organic search traffic from Bing and Yahoo!. Site Explorer services will not be available from November 21, 2011.