Bing Webmaster Tools ";no longer" requires Silverlight. Now, if you login to Bing Webmaster Tools without Silverlight installed on your computer, you can see all the reports, graphs and charts that you were unable to see days ago.
Now with the new HTML5 support, all this wonderful data is now available to any modern browser -- with or without Silverlight.
In July 2010, Bing revamped Webmaster Tools adding some additional reports and information but didn't remove the requirement of having Silverlight to view the detailed reports. Vanessa Fox said this was a major draw back to the tool since "most of the data is available only graphically, and not as a download, without Silverlight, you basically can't use Bing Webmaster Tools at all."
Bing has yet to make an official announcement.