Long has a nice scoop about Windows 7 M3 features being leaked … by Microsoft. You gotta love legal.
BitLocker™ Drive Encryption
What this feature does
BitLocker Drive Encryption (BitLocker) is available on computers running Windows 7 Enterprise Edition and Windows 7 Ultimate Edition. Should your computer be lost or stolen, BitLocker protects your data by helping to prevent offline software attacks. Turning on BitLocker encrypts the hard drive where Windows is installed, including all information that is stored on that drive.
Device Stage
You can turn this feature off by going to Devices and Printers in Control Panel. Right-click your computer icon, and then click Device Installation Settings. Select “No, let me choose what to do” and click to clear the “Display enhanced device icons…” check box.
Driver Protection
Driver Protection helps prevent the operating system from starting drivers that are known to cause stability problems.
Gadgets
Gadgets are programs that run on the desktop and provide at-a-glance information, and easy access to frequently used tools.
HomeGroup
A HomeGroup allows you to easily link Windows 7 computers on your home network so that you can share pictures, music, videos, documents and devices. It also makes them ready to stream media to devices on your home network such as a media extender. You can help protect your HomeGroup with a password, and you can choose what you want to share.