Well, let's start with paid advertisers. When searching for information about products, Google's image space is 100% pay to play. Of course, this means that all the sites included are paying more to be featured in search results and you know they aren't absorbing those costs. This is true in the US and 11 other countries:
Videos. Search for videos on Bing and then just hover over an image to see a preview of the video (including Vimeo and other sites). This is sooooo much faster than having to visit each page in YouTube.
Images. While Google offers comparable filtering tools for several categories (e.g., picture orientation, color, B/W, lineart, etc.), Bing also adds licensing filters. This is a must if you use pictures for any public viewing.
Biggest difference of all...
This:
https://www.google.com/intl/en/policies/privacy/
vs. this:
Microsoft Privacy Statement
Microsoft even has an entire website that explains your options and walks you through privacy options:
Your privacy and Microsoft personalized ads
Last year, Google's revenues totaled $58.1 BILLION, of which $50.5 BILLION was from advertising. Google users are not their customers, they are Google's product - an audience for advertisers. Although Microsoft is endeavoring to make Bing self-sustaining, only about $2.5 BILLION of Microsoft's $75 BILLION in revenues last year came from Bing advertising sales. Microsoft's primary mission is to sell software, services, and hardware. Their survival is not dependent on selling information about me.