Currently the purpose of the tool is to validate whether your PPC ads are showing for specific keywords. That purpose will remain intact, but new features will expand the tool's capabilities--increasing it's importance for marketers. The new name is Bing's "Ad Preview and Diagnostics Tool," and the added diagnostics application will help reveal why your ads are not showing for a particular keyword.
The new tool will help identify which keywords within your PPC account could be used in response to a search term but being disqualified due to issues with:
The feedback component of the new tool will help marketing companies and businesses better position themselves within the competitive ad marketplace. This tool will become a vital resource for eCommerce marketing and any strategy that involves competitive keywords that require dynamic and frequent optimization.