1. Search results pages are more useful
I searched for the term "polar bears" just to do a side-by-side comparison of the results, and here's what I got.
Google: polar bear ads, polar bear information, polar bear news, side bar: polar bear animal profile.
Bing: polar bear images, polar bear information, polar bear news, polar bear videos, side bar: polar bar animal profile, related searches, related images, polar bear ad, recent Twitter mentions.
2. Bing News results are more robust
I did a search for my company, Five Stone Tax Advisers, to see if we were picked up from a recent PR campaign we did. Bing's news results were about 12 times what Google's were. Some major news sources were missing from Google's results. See screenshots. Additionally, Bing News allows you to sort by top stories, U.S., World, Local, etc.
Competition and market share are what keep us from becoming North Korea. When I can support something that isn't Google, I'll do it. I already spend tens of thousands of dollars a month with Google via PPC. It takes me a quarter the spend on Bing to reach the same number of people in my particular industry. That in itself is reason enough to use Bing as my preferred search engine.