I've begun to visit Bing at least once a day. I don't believe that it offers a better search engine than Google, but the daily rotation of interesting images is worth a quick peek.
Microsoft has created a reason for me to come back every day. Although that reason is far-removed from the core functionality of Bing, it does get me to at least give it a glance. They've won one battle - capturing my attention. But they've failed to build a superior product so far.
So is this worth anything? Will the novelty of interesting/fun/cool images wear off? Probably. But they do have a few more months before that happens. Bing has its foot in the door but doesn't have the body to walk through. This seems like quite an expensive approach, but for large companies it's viable.