Just recently Microsoft came with its warnings for approaching support deadlines:
Many people I know were confused with differences between Microsoft’s mainstream and extended support. The end of mainstream support in actually not that big of a deal. All it means is Microsoft tells us “Hey, we’ll no longer going to add any new features to your Windows 7, but don’t worry about updates, patches and fixes you’re good until 2020.”
For those still with Windows Server 2003, however, there is less than one year left!