Microsoft has trademarked the name Swivel as its mobile operating system. The trademark has been filed in September last year even while it was busy showing off the latest version of Windows Mobile 6.5.

Microsoft eventually plans to do away with versions of Windows Mobile and will call it simply Windows Phone. So what could the Swivel be?

It really does not make much sense for Microsoft to rename Windows Mobile (or Windows Phone, for that matter) as it resonates with its Windows OS on the PC platform.

We believe, this could be an internal codename for some upcoming version of the mobile OS.