Well. I'm glad some new discussion more productive than "update for 1.2.5!" is being generated for RS, but I'm kind of sad the original didn't go much further. I would like to see a lot more go into the Fusion Reactor. I could care less about destruction beyond the nuke rocket. Space exploration is nice, but it doesn't really fit well with minecraft's mechanics. Maybe it would fit as sort of an addon or similar mod to Mystcraft, where other planets are very simply dimensions, without much travel through actual space.
What I'm interested in is the fusion reactor. I would like to see fusion reactors become more automate-able and more to be done with them. It's like it adds an entirely new method of power generation, but there's nothing that uses it. I'd like some more machines involving the new method, maybe make it a new tier of power generation and run machines off the Extreme or Ultra-High voltage. Maybe, even, the fission and fusion reactors can be combined to create a "Mini-Star" which generates much more energy for the same amount of fuel. I find myself really wishing I just had that new super-conductive cabling, which is even more efficient than the Glass Fibre Cabling, and would work well with some mods (like the lightning rod mod) and their issues in dealing with higher voltage
costs/generation. It would add a whole new platform for mods, and maybe Nuclear Control can add some stuff for the new generators.
Some ideas, for anyone who wants to run with them, that could potentially use this new tier of power generation (or just the old one) could be the Singularity Machine, which would be capable of creating singularities to massively compress items, at the cost of an extreme amount of power. It wouldn't be like the singularity condenser from advanced machines, it would be something new which could take any item and add it to a "Black Hole" item, which is essentially a repository for matter. You pop the black hole into a mass fabricator or something like it, and it converts it or "decompresses" it over time into UU matter or something, kind of like a ginormous stack of scrap. Maybe you could even hook one of these up to a rocket and launch it off to an enemy where it would create a singularity where it lands, sucking everything around it into a black hole before disappearing. Maybe you could turn it into a singularity miner, which mines things like a laser or drill, but much faster, and adds it instantly to a black hole in it's inventory.
Then there's other ideas for this new age of power, like a plasma generator that creates a new liquid or item that's a super version of lava. It could burn through blocks, destroying their items, and hurt anything that even gets close to it. Maybe you could have a plasma-cutter tool, or a plasma cannon weapon which is like a re-chargeable gun that can destroy blocks as well as enemies. Maybe you can make a plasma bomb and attach it to a rocket to spread plasma all over the target, damaging anything near it and burning holes through any blocks it touches. Maybe you won't need a plasma generator, but it would be a sort of by-product of a "Mini-Star". Maybe you could make a Plasma Injector (made from plasma of course) that would reduce the startup heat/electricity costs of the fusion reactor and the mini-star.
The possibilities when looking to modern science and science-fiction are endless. You could even go for time travel integrated into singularities, if you want to go that route of Astrophysics Theory. Maybe the mod could just be called, "Industrial Science" or just, "Science."