If you really think about it, Windows Mobile 6.5 isn't really an old mobile OS. In fact, it was launched just a few months ago - albeit as a stopgap OS till Windows Mobile 7 (as Windows Phone 7 Series was known back then) arrives. Well, Windows Mobile 7 just arrived and goes by the Windows Phone 7 Series moniker - but what happens to Windows Mobile 6.5? Well, it stays. Microsoft will be re-branding Windows Mobile 6.5 as Windows Phone "Classic" and handsets based on this "old" OS would still be available for quite some time in the foreseeable future. While Windows Phone 7 Series will power high-end devices, low-cost phones will continue to be sold with Windows Mobile 6.5 installed.
Windows Mobile 6.5 might also be made available in select markets only or for companies who might have issues upgrading to Windows Phone 7 Series and would like some time before they can upgrade. Additionally, Microsoft seems to believe there still is a sizable user base of people who would want to use Windows Mobile 6.5 for its vast applications support. So, if you thought Windows Mobile 6.5 was dead, think again. It might be on its last legs but is sure to hang around for a while.