End of support for Windows Server 2003/R2 by Microsoft means not only lower efficiency and much lower security – but also more investment for you!
Microsoft has stopped releasing any updates for Windows Server 2003/R2. Imagine the impact it will have on your infrastructure.
Windows Server 2003/R2 is no longer compliant with various standards and regulations. This could mean organizations like Visa and MasterCard no longer doing business with you.
With you having to incur added costs for intrusion detection systems, more advanced firewalls, and network segmentation, maintenance costs for aging Windows Server 2003 hardware will likely increase.
Virtualized and physical instances of Windows Server 2003 are now highly vulnerable and would not pass a compliance audit.
Look at the end of support for Windows Server 2003/R2 as an opportunity to evolve- move to Windows Server 2012 R2, or to the cloud!
Take benefit of the "hybrid model" with Microsoft Azure Infrastructure Services using the same virtual machine format as Windows Server - get a super-consistent experience across datacenter and cloud deployments.