ending of Windows XP support, some were still surprised! So, it’s never too early, especially for businesses, to start planning their move off of the now 5yr old OS.
It would be in users' best interest to start planning migration to Windows 8 or 8.1 immediately. However, with Windows Threshold (Windows 9) scheduled for release next spring, you may consider holding out to upgrade then. Of course, by that time, there may also be a 2nd update for Windows 8.1 as well - also expected by next spring.
We've heard reports that the vast majority of Win32 applications that run on Windows 7 should run on Windows 8 and beyond, but enterprises in some regulated industries may be restricted to using software that still uses formal ISV support.