Microsoft Windows Server 2008 R2 will be the next version of the Windows Server operating system from Microsoft. Building on the features and capabilities of the current Windows Server 2008 release version, Windows Server 2008 R2 allows you to create solutions that are easier to plan, deploy, and manage than previous versions of Windows Server.
You can get the details on the product from the Windows Server 2008 R2 site
Additional Resources: http://www.microsoft.com/windowsserver2008/en/us/R2-resources.aspx
This software is for evaluation and testing purposes. Evaluating any version of Windows Server 2008 R2 Beta software does not require product activation or entering a product key. Any edition of Windows Server 2008 R2 Beta may be installed without activation and evaluated for an initial 30 days. If you need more time to evaluate Windows Server 2008 R2 Beta, the initial 30 day evaluation can be extended to August 1st (at which time the OS will become inoperable) by entering the product key below for your selected edition.
You can download the ISO images from http://www.microsoft.com/downloads/details.aspx?FamilyID=85cfe4c9-34de-477c-b5ca-75edae3d57c5&DisplayLang=en
Windows Server 2008 R2 Beta Product Keys for Evaluation Windows Server 2008 R2 Beta Enterprise (7000.0.081212-1400_server_en-us-GB1SXFRE_EN_DVD.iso)
I have not personally installed it you but will likely get to it this weekend and give you my feedback. I have heard and read great things so I am really looking forward to working with it. At some point, the download evaluation will be cut off. If you would like to get working on playing with any of Microsoft's new products Including Windows Server 2008 R2 (maybe even after the cutoff). I can get you setup on the Momentum program (Early Adopters Program). If you are not on the momentum program and want to get started deploying any new product from Microsoft (including beta) let me know and I will get you started. Microsoft's Momentum program will help you along the process of deploying our newest technologies. You can send the request to me via a link to my email. Please include your name, company name, email address, phone number, and address with "Add to Momentum 2008R2" in the subject. In return, I only ask that you keep me in the loop on progress and problems so I can personally make sure you have success. You can send the email from here (http://blogs.technet.com/danstolts/contact.aspx) I would also encourage you to subscribe to my blog for additional useful information as it becomes available.
I was on the 2008 R2 bandwagon since day 1!