Microsoft today touted the five themes of the upcoming Windows 7 client OS and made a pre-release version of the software available for developers at the company's Professional Developers Conference (PDC) in Los Angeles. A full, API-complete beta release that developers can begin using for app development is planned for early 2009, said Debby Fry Wilson, senior director of Windows product management at Microsoft. General release is planned for early 2010.

Microsoft's five key themes for Windows 7 are:

[ Will the new Microsoft OS be better than Vista? Join the Windows 7 conversation in Randall C. Kennedy's Windows Sentinel blog. | See Tom Yager's first look at Windows 7. ]

Mobile computing. This includes improvements in energy efficiency, security, and the ability to move in and out of networks.

Services design. The OS will focus on core capabilities and take out client applications focused on communications and user experience. Instead, these services will be offered (likely for a fee) on the Windows Live cloud service for those who want them.

Personalization. The OS will adapt to how a user interacts with a PC and how the user wants the user interface to look and feel.

Entertainment optimization. This includes features for device management and "media experience."

Compatibility and stability. Microsoft says the revised OS will focus on application and device compatibility and ensuring that applications and devices work properly -- an apparent response to the problems with Windows Vista. "Our goal is to have any application and device that works on Vista to [be] compatible with Windows 7," Wilson said.

Other capabilities include location-aware printing, in which the OS knows whether a printer is at work or at home, and home networking capabilities. Also, Microsoft says that users will be able to access their company's intranet sites without requiring a VPN. Multitouch capabilities a la those in Apple's iPhone and new MacBooks -- as well as in Microsoft's Surface technology -- also are planned.