Windows Home Server V2, code named 'Vail', is a home server operating system in development by Microsoft to succeed the Windows Home Server operating system designed for Small Office/Home Office (SOHO). This is a beta of their new version 2.0 of Windows Home Server, which from appearances, looks much like Windows 7. The sudden public beta announcement has somewhat surprised many Microsoft followers. The code base built of off Windows Server 2008 R2, and only a 64-bit version is available -- as 32-bit OS slowly cede popularity to their 64-bit brethren. It is designed to easily get you setting up a home server for yourself, so you could, perhaps setup up a file server, give your computer remote access, stream media, automate backups, or some of that other simple server stuff.

(Source: Science & Technology/ Wikipedia)