VMware released vSphere and ESXi 5.1 Update 2  on 16th of January, 2014.

What’s new

• vCenter Server is now supported on Windows Server 2012 R2
• Additional Guest Operating System Customization Support – vCenter Server now supports customization of the following guest operating systems:
  • Windows 8.1
  • RHEL 6.4
  • Windows Server 2012 R2
  • SLES 11 Service Pack 3
• Database support added for Microsoft® SQL Server® 2012 Service Pack 1