While Samsung isn't the first to come up with the idea of running two mobile operating systems on a single devices, its appraoch differs from the current dual boot setup. The current solutions available limits users to one OS at a time. What Samsung is proposing allows users to run both OS side by side at the same time. The patent filing shows that users would be able to swutch between the two with a tap of a button, share files, folders and resources between the two. And also run Android and Windows Phone apps side by side as Windows.
However with the current state of the Windows Mobile ecosystem, its unlikely that Samsung would be making any of these devices any time soon.