R2 a.k.a. “Release 2” is a vehicle Microsoft has used in recent years as a midway release between major software releases. The Windows Server team first adopted this with Windows Server 2003 R2. Multiple R2’s have been released since then, in the System Center area this includes SMS 2003 R2, Configuration Manager 2007 R2, System Center Essentials in SBS 2003 R2, System Center Virtual Machine Manager R2, and Operations Manager 2007 R2 (in development).
R2 releases are typically a compilation of earlier service packs to the base product plus some additional new features and functionality – not enough to warrant a new product release, but enough that Redmond decides not to just include the updates in a service pack. Customers with upgrade rights on the base release of the product through Software Assurance (SA) can upgrade to R2 at no charge; others need to purchase R2 licenses for those products.
One rationale for R2 software is to give those organizations purchasing Software Assurance return on their investment – while SA contracts are typically for three years, many products do not have new releases within a three-year period.
On the other hand, those organizations without SA are finding themselves relatively early in the product life cycle choosing between purchasing a new license, or making do without the new functionality until the next major product release. In some cases, the updates are not that significant (unless that one piece of functionality is something you can’t live without!), although in others – such as announced functionality for Operations Manager 2007 R2 – there are some major new enhancements.
(oh, and if you haven’t noticed regarding the upcoming Windows Server 2008 R2 – the internal codename is Windows 7 Server!)
