Considering that the thread is "purely theoretical", I think the likelihood of it happening is pretty moot for discussion. Clearly, the Siegel/Shuster copyright plus Time Warner is the most financially viable situation and where I ultimately expect Superman to end up. The only way Superman ends up elsewhere is if the heirs totally ignore financial realities or someone else makes a reckless offer for the rights.
Marvelman/Miracleman probably has more value to Marvel based on what they potentially could get to use.
Marvelman/Miracleman probably has more value to Marvel based on what they potentially could get to use.