Two features I haven't found a replacement for yet:
1) Wireless Redstone. This isn't RP2, but as I understand it, CB's WRCBE depends on RP2. I'll be testing out Ali4z's wireless redstone mod this weekend. Anyone else have some experience with Ali4z's or another wireless mod?
2) compact logic circuits. I know MFR has the RedNet Controller, but that seems like overkill for when you just want a simple T-flop, timer, or state cell. Compact yes, but a lot of ingredients go into that controller.
Yeah, not a GT fan but not hatin' on those that are. Besides, I've removed IC2 from my modpack.the most recent gregtech versions have wireless redstone that you can attach to your machines, and its own simple logic blocks, that work in 3 dimensions.
I'm currently coding my own replacement for RedPower
At the time of this post I have almost all the important bits of RP:World and I made it as a replacement - it uses the same damage values/metadata as RedPower does (easier converting from one mod to another).