I too am seeing this with my site. It really appears to be up to Bing with what gets indexed. For the most part Bing indexes the Page Titles, but not always. Sometimes the Meta Descriptions match between Google and Bing and other times Bing will index some copy on the page. The copy isn’t always the first to appear on the page. I had three blurb boxes on a page and Bing indexed the copy from the third blurb. I can only assume Bing evaluated the description and the page copy and choice what it determined fit their criteria best.