Microsoft's Windows Blue initiative was first discussed in November, and it's supposed to be an internal plan under which Microsoft will issue frequent updates to its existing platforms, both on the PC and on mobile devices. As ZDNet's Mary Jo Foley explains, Blue is expected to deliver updates for "Windows 8, Windows Server 2012, Windows Phone 8 and Windows Services," which means it's an all-encompassing name for a grand scheme of updates, not just a single one of those platforms.

A new job posting for a Microsoft employee confirms the name "Windows Phone Blue."  The text specifically says: "As a development lead you will hire and manage a team of top-notch developers, be personally involved in designing and coding features, and work closely with PM and Test counterparts across multiple orgs to help realize the vision of building high quality excel app for Windows Phone Blue (emphasis added)."

That reveals two things: Microsoft is indeed working on "Blue" updates for various platforms, and that a new, better version of Excel is planned for Windows Phone. We imagine we'll hear much more on this project during 2013.