The company was granted the patent on July 24 and received the rights to combine a real world picture with virtual skywritings that are associated with a mobile device's location. The idea is to make this a location-based service as a "virtual skywriting service" and will provide previously selected skywritings for the device's location.
There would be several interesting concepts for such an idea, for example to immediately combine skywritings with any location, but this is not explicitly part of the patent submitted in June 2011. The patent simply refers to two separate processes, in which skywritings are "authored" by users of mobile devices and then are submitted to a virtual skywriting service. Only when submitted and listed, the skywritings then become available for integration in a picture.
Of course, the first problem with such patents are that there is no real product that Microsoft is offering. The only virtual skywriter is the one published by OpenProcessing made available via GPL. It is rather unlikely that Microsoft had no idea about this basic approach and, even if it added a mobile and service component to it, it is an example of the strange patent world we live in.
Another controversy has been brought up by GeekWire, which got its hands on the patent about a month before it was granted, and noted that the patent itself includes a copyright violation. The patent includes an example virtual skywriting image that was taken from a real world skywriting patent, without attributing the image in any appropriate way. Of course, humans make mistakes, but this patent overall has a certain spot in the contest of the most useless patents of the year.