From Microsoft:

Today, Microsoft announced the release of Windows Storage Server 2008 to OEM partners.

Windows Storage Server 2008 (WSS08) is built on the strength of Windows Server 2008 file serving. It is delivered by partners as an appliance, and helps customers achieve a simplified deployment and management experience while complementing their existing infrastructure technology.

Windows Server team blog:

I’m pleased to announce the release of Windows Storage Server 2008 (WSS08) to our OEM partners.  WSS08 is built upon Windows Server 2008 – the industry-leading file services platform. WSS08 includes additional advanced storage capabilities such as file de-duplication and an iSCSI software target for unified file- and block-based storage. We deliver WSS08 through our partners as a storage appliance so that the hardware and software are delivered and supported as a complete solution that is optimized for its storage role.  Microsoft customers benefit from enterprise-class storage capabilities without sacrificing the flexibility, reliability and familiarity that they expect from Windows Server. This release is a continuation of Microsoft’s commitment to deliver innovative file and storage solutions to our customers through our partners. 

Beginning May 7th, you can learn more with the on-demand TechNet Webcast: Introducing Windows Storage Server 2008.

Our OEM partners will be announcing their Windows Storage Server appliances over the next several weeks. While they are gearing up for release you can learn more about the file services in Windows Server 2008 that WSS08  is built on and get ready for the best storage appliance that we’ve ever delivered!