Now for my own comments on this topic.
It will never happen! At this point in time I am not convinced that it would be the best thing for us even if it could be accomplished, but I understand the desire to have our limited resources all working on the same OS, to improve the speed of progress. It is just not possible, unless one person or group could buy out all of the groups, and even then there is no guarantee that the community would follow the new path and decisions made by this one person or group who had gotten control of all existing Amiga and Amiga inspired platforms.
There are too many differences of opinions on which direction is the best for any one of those choices to be considered the ONLY right choice for all of us. Each choice has it's own life now, it's own user base (though many users are involved in more than one of these choices), it's own developers, and it's own vision for the future.
Nice dream, but a waste of time dreaming of something that can never happen.
Edit: Yasu, you beat me to the punch.