The old operating system has since been discontinued with the launch of Windows Phone 7, and Microsoft is slowly phasing the OS out.
In an email to Windows Mobile 6.x customers, the company says:
Beginning May 9, 2012, the Windows Mobile 6.x Marketplace service will no longer be available. Starting on this date, you will no longer be able to browse, buy or download applications directly on your Windows Mobile 6.x phone using the Windows Mobile 6.x Marketplace application and service.
Applications and games acquired from the Windows Mobile 6.x Marketplace service installed on your Windows Mobile 6.x phone will continue to work after the service is discontinued on May 9, 2012. However, additional downloads of these applications and games from the Windows Mobile 6.x Marketplace service will no longer be available.
To break that down even more simply, as of May 9th, if you are still running a Windows Mobile 6 device, you will not be able to download any new apps via the store, or get updates. If you ever hard reset (factory wipe) your device, the apps will be lost forever, as well.
Written by: Andre Yoskowitz @ 9 Mar 2012 21:35