Last night, Microsoft announced a new functional update for Windows Home Server (WHS) called Power Pack 2 (PP2) that improves the product's remote-access and media-sharing capabilities. The company also revealed that the OS will now be made available to MSDN subscribers, dramatically increasing developers' ability to create add-ins for the system.

PP2 is the second functional update to WHS, following the July 2008 release of PP1. Unlike PP1, which included a wide range of updates and fixed a controversial data-corruption bug, PP2 focuses on just a few key areas. It improves and simplifies the system's remote-access functionality, which requires low-level interaction with the user's home network router. And it adds a number of media-sharing features, including Windows Media Center integration and support for MPEG-4 (H.264 video and AAC audio) content streaming.

PP2 also includes a number of other changes—such as support for the Italian language, an improved SDK for developers, and a simplified setup routine—that will affect only new users. PP2 is a free update for all WHS users and will be delivered via Windows Update beginning today. It's the last functional update for the first-generation WHS software, which is based on Windows Server 2003. A second-generation WHS version is expected sometime in 2010.

In addition to delivering PP2, Microsoft announced last night that it's making WHS available to MSDN subscribers, thereby increasing the availability of the system to developers. Microsoft announced in January that about 70 third-party functional add-ins were available for WHS, but that number has already jumped to over 100. The company hopes that by expanding the potential WHS developer base through MSDN, the number and quality of WHS add-ins will also expand.

Key functional improvements provided by third-party WHS add-ins include disk defragmenters, antivirus solutions, and off-site backup solutions. In addition, some of Microsoft's hardware partners are including their own unique add-ins with their WHS machines. HP, for example, includes an iTunes aggregator that collects all the media from iTunes-based PCs in a home network and shares them from a central location.

You can find out more about WHS PP2 in my overview on the SuperSite for Windows