There is now a more-or-less firm best-before date for Microsoft’s two current Windows Phone operating systems, with Windows Phone 8 having official support dropped in July 2014 and Windows Phone 7.8 following suit in September of the game year.
The exact dates that WP 8 and WP 7.8’s support will drop away are 7 July 2014 and 9 September 2014 respectively, giving users some 18 months of updates from Redmond. Windows Phone 7.8 fans are unlikely to find that their handsets can be updated so a switch to whatever is Microsoft’s current OS iteration will likely be a plan.
Of course, before the two OS’s are outdated there will likely be a replacement version that Windows Phone 8 users can upgrade to but it is always nice to know in advance when your operating system will become completely outdated. That way you’ll be aware that you probably shouldn’t pick up a new Windows Phone 7.8 device at the beginning of next year (or that you should stock up before they no longer exist).