Hmm, part of me thinks this would be great, as these mods seem to work extremely well together, and I agree the overlap is really annoying.
At the very least, like some have said, I do wish they would if not completely merge their mods, then at least take the basic items that they share and don't have any mod dependent code like the ores, and make a seperate mod plugin. They all need forge at the moment, so requiring another mod that only contains the ores they share and whose behavior is identical would be a good thing, also it should be extremely easy to update the ores alone between versions, so having them as a dependency is not a big issue. Since the only use of the ores is to craft things out of them, and since adding new crafting recipes does not require modifying the code of the items it is made out of. This would be a simple and helpful measure.
Still, I do wish that they were more compatible with each other and you could use the power from one to power machines/engines in the other, and maybe use the piping system to pump lava directly into the geothermal generator, or water into the water generator.
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The thing is, such a shared mod could prove to be a nice library for other technic-esque mods to work with. If it included basics like "how to use power generation from BC/IC/Whatever" in the code you could easily allow people to use this one library to make it compatible with the other mods entirely, build off their resources, and just in general create a whole genre/base for mods to work with, like a whole Modforge dedicated to industrial mods.