Sure, we've seen plenty of multi-touch implementations on the Microsoft Surface and other Microsoft projects (read Courier), but this one, brought to our attention by Long Zheng of iStartedSomething, breathes new life into the already creative world of multi-touch. While pen and touch each offer their own powerful capabilities, the combination of two presents endless possibilities. Microsoft is calling it "Manual Deskterity"--an obvious pun on "manual dexterity."
In the video below, you will see Microsoft demoing the use of fingers and a pen at the same time. Notice how the Surface is able to distinguish between the two. In the real world, doing both actions together is a no-brainer. Microsoft is aiming to recreate that natural interaction within its software. Such power will enable users to do what was never before possible in a digital world. This concept would work amazingly with Microsoft's upcoming Courier--an obvious choice for such an implementation.