Last week's big Microsoft news was the release of Windows 8.1, but it wasn't just the desktop that saw a refresh. Windows Server 2012 R2 and System Center 2012 R2 also saw official release.
We've known the main feature additions to R2 since early June. Businesses looking to install the software have also been able to download the final release since September via a TechNet or MSDN subscription. Microsoft rapidly backtracked on an unpopular decision to block release until the manufacturing launch date for those customers after a major outcry.
Announcing the General Availability of the R2 Wave of Products [Server & Cloud Blog]