Microsoft will release Windows Server 2008 R2 sometime in the fourth quarter, the company said Monday at its annual TechEd event for IT professionals.

The company also announced that a test release of the next version of SQL Server would be available for limited release in the second half of this year, and it detailed new features for each.

The near-final release candidate version of Windows Server 2008 R2, made available for download last week, includes a number of new features. At Microsoft's Professional Developers Conference last October, the company announced that Windows Server's Hyper-V virtualization would support up to 32 logical processors, but Microsoft has now bumped that number to 64 for companies looking for more virtual machine density.

Virtualization improvements are among the key new features of Windows Server 2008 R2. Another new feature, Processor Compatibility Mode, will allow Windows Server instances to move between machines with different CPU types. That will improve the usability of one of Windows Server 2008 R2's other new features, live migration of virtual machines.

"One of the iniquities with our clustering solution today is all of the nodes in a cluster need to have an identical CPU type in order to live migrate a VM from one machine to another," Ward Ralston, Microsoft's Windows Server group product manager, said in an interview.

One new feature, the File Classification Infrastructure, gives IT pros the ability to automatically classify files and set policies for those files based on their type. For example, companies could set all documents with the term "Internal Use Only" in them as a type named "secret," and set specific security and backup policies based on that classification. Companies could allow employees to classify files. Another set of files, possibly classified as something like "low business value," could be set to automatically delete a year after creation.