Microsoft will no longer offer Clip Art. As an alternative, the company is pointing users to use Bing image search instead. Which is fine, because that's what everyone was doing anyway. Except maybe for the Bing part.
For years, Microsoft's Clip Art library was a way to get images when finding some quick art to illustrate a Word document or Powerpoint presentation was difficult. The internet has all but eliminated the need for software to ship with bundled stock art, and indeed, Microsoft had already migrated its collection of Clip Art to an online portal.
But alas, most people weren't even bothering with the portal any more, according to Microsoft. In all likelihood, most were turning to Google's image search, so it makes sense that Microsoft might try, however hopelessly, to get people to use its own portal instead. (Microsoft for some reason took down its announcement, but you can find the cached version here.)
In the event that you still want to insert art into a Word document, Microsoft provides detailed instructions on how to get images from the internet without breaking the law. Basically, make sure that the images you want to use have a Creative Commons license or otherwise labeled for reuse.
Farewell Clip Art. We didn't know we missed you until you were gone. [Microsoft (cached)]