I am having a hard time though figuring out why the vast majority of people would be interested in running multiple platforms on their phone. This isn't just for developers either. According to HTCPedia VMWare is working on this technology on a high end device using a 1GHz Snapdragon processor. VMWare has commitments from at least one carrier each from the US and UK to start testing in 2011 and ship in 2012.
As impressive as the Snapdragon is, we are likely to see even faster devices by then and I have little doubt the hardware can handle switching multiple operating systems. I am just not sure why. Ignore the developer or the average geek that is able to answer the question "Why would you want to do that?" with, as a good friend used to put it, "Why? Because I can." That audience is too small for a carrier to consider.
Who will they target with this? Theoretically, the primary reason would be to access applications from both platforms on a single device. Are there so many killer apps on both platforms that people would be willing to switch operating systems at the swipe of a finger? A year or so ago, when the old PalmOS platform still mattered, there was a virtual environment you could load on Windows Mobile to run some of your favorite PalmOS apps. The VM was of limited interest though, even for a platform that had years of history and some extremely well known apps. I am just not seeing either WinMo or 'droid apps having that kind of appeal. Do you have any good reasons the average Joe would be interested in this?