Would it be easy (or even possible) to convert EU from some sort of machine into a portal to the nether or the end even? This would provide a way to get to the end for those who have worlds that came before 1.8(?). I thought of the nether as an extension to this idea.
So here's how I would have it work. The block is supplied with energy, about 100,000 EU, and it transforms into a nether portal. Not a big 14 block nether portal, an actual nether portal block. Providing it with 2,000,000 EU would turn it into an end portal. These numbers are, of course subject to change. If this seems too hard to do, can we get a plant that has the same effect only without energy and just time? I need more uses for my 20 nuclear reactors >:)