I personally think that dual boot is good for a start but I do not think it is the long term answer. I loved dual boot on my laptop as it gave me a chance to play with Ubuntu with knowing I had the safety net of being able to go back to windows when I wanted. However, with phones it may not work as well as you generally want continual access to your app such a scat and email. The long term answer is to make something nice and new, something different and most of the time that means not android or apple. Also the as that people need and use need to be made available on touch.