I would think that ought to be fairly comforting to someone who is risk averse. One or more of the above companies companies could disappear and there would still be options and ongoing active development.
It seems to me that what Michael said above is one of the basic tenets of the Free Software and Open Source movements: if the software you've chosen to build your platform around is Open Source you can always hire someone to make changes to the code because you have the right to. Of course by aD changing licenses I personally feel that they've lost all connection with the Free Software and Open Source movements and are now just "in it for the money."
