As of today there are two months 23 days and some hours to get modern
The benefits are priceless the consequences of not doing so could be excessive.
From a programming standpoint “Windows 8.1 brings enhanced support for in-app file management, new ways to interact with user content through libraries, and the ability to push your app’s unique content to the Windows index. This means that your app can easily access user content and make its own content easier for other apps to discover.”
http://msdn.microsoft.com/en-us/library/windows/apps/bg182881.aspx
For the user this enhanced file structure great too, because it is not all that different from what you are used to in Windows XP, Vista or Windows 7. To get to all those pieces and parts of the new Windows 8.1 experience, the path to the files related to your account profile on one’s computer is stored in the following location: C:UsersusernameAppDataRoamingMicrosoftWindows.
The time to get to modern is now.