According to a job offer listed on Microsoft's web page, the company is to develop a new, market disrupting software product meant run on the Windows Phone platform. Unfortunately, details about the project itself are scarce at this time, but it would not have been classified as a “top secret project,” now, would it? Some of the clues, however, suggest that the government may be one of the potential buyers, and the software will have something to do with security clearance.
What Microsoft is getting ready to pull out its sleeve is anybody's guess at this moment, but some are speculating that a proprietary IM application with advanced security features is in the works. If you feel like making a guess as well, feel free to drop a line in the comments section below.
source: Microsoft via Neowin.net