Bit Tech reports Windows 8 is said to offer an app store and texting features. The latter function may come in handy on tablets and other portable devices.
Interestingly, the source code also appears to imply that Microsoft is planning to build in geo-location logging. This could enable the company to track a Windows 8 powered machine over time - a feature obviously aimed at tablets and laptops. It will be interesting to see what happens to this feature in the final build of the OS, however, given the privacy furore that surrounded Apple’s acknowledgement that it used similar technology earlier this year.
Finally, there's also a hint that Windows 8 will come with SMS features built in, which would make sense given the operating system's tablet-friendly interface.