It's worth a read of this document, even if it doesn't give you the recipe for the secret sauce.
Bingís goal is to help the user complete their search tasks as efficiently as possible. To do this, Bing:
Optimizes titles for relevance to the user. Titles are very powerful when it comes to showing how a site or document is relevant to a userís query. Optimizes snippets. Snippets also help the user differentiate between search results at a more granular level. Optimizes display URLs. Users look at URLs to validate the source of information and gauge its authenticity. Bing tries to make it easy to see who is providing the information. How Bing Chooses a Web Page Title For Its SERPs [blogs.bing.com]
Bing has a complex set of rules that combine many different pieces of information to build titles, snippets and URLs in order to provide the optimal search experience to the user.
This would mean that if you study enough Bing titles vs their originals you can extrapolate the set of rules, eventually. I somehow doubt that the rules are set in stone however, if they use exceptions or add a touch of randomness to the recipe it would take forever to figure out.
You're probably better off spending that time creating new content, the sauce must not be recreated or it will be changed anyway.
I must make the best titles ever as I just checked about 30 pages and it's serving them up verbatim. I'm a minimalist and don't keyword stuff those titles so maybe they don't need rewritten, who knows. :)
The only thing I saw that was odd was in the same basic query it picked a blog list of posts for one query and a slight change made it pick the exact blog post page instead.
I came up top 10 either way, so that's cool, but the criteria for choosing which URL to serve with the same content, very odd.
Does appear to merit a bit of reverse engineering to see what's going on at Bing but I wouldn't even try to fathom the full depth of the algo, just find what appears to be the key elements and leave it at that, good enough.
From where I'm sitting, my sites are ranking like crazy so I'm not going to do anything as it's not broken.