Brett Yount from the Bing Webmaster Center said the way to be included in Bing News is a manual process. You simply need to email firstname.lastname@example.org and wait to hear back.
What if you don't hear back? Brett suggests emailing again:
There should be confirmation from the review team. If you did not get one, I suggest emailing them again.
Yahoo News and Google News are tremendous traffic drivers, but Bing is gaining market share, according to some. So it cannot hurt to be listed.
Forum discussion at Bing Community.