Well, this is disappointing, but I kind of saw it coming, seeing that TE3 pretty much has its' own independent power source now, and is practically its' own mod, rather than an "expansion" (I think to Buildcraft?). I guess I'm a bit of a traditionalist in this, but IC2, BC, Forestry and RailCraft either going, or possibly going, to me, takes a bit of fun out of it. Sure, IC2 and TE have different power systems (IC2 and BC even had different power systems from the early days - EU and MJ) - they can be converted with the power crystals mod (just saw some controversy surrounding that today, though...).
Anyway, I liked having the option of using TE early game for the extra ores, and then moving on to IC2 for faster ore production (overclocker upgrades) as I get into more late-game ore extraction - or at least trying (like BC Mining Drills). Hopefully, the other 3 don't go. I enjoyed having different types of systems in a modpack for different styles of play (early industrial tech based, like Railcraft, modern tech based - IC2/Forestry, Future-tech - AE2 automation, magic based, etc.).