FTB is deliberately making it so Thermal Expansion is the primary source of power from here on out, meaning IC2 is finally getting its well deserved execution.
This is amazing and I approve. IC2 is just... meh. The crafting recipes are incredibly annoying and TBH underpowered, the machines are painfully slow without overclockers, most of the textures are ugly, and it doesn't seem to have the features of a modern mod. Thermal Expansion is prettier, apparently has a better API, more user-friendly, and still balanced. A lot of mods already support it and it's only been popular for about one version. Extra Utilities has a bunch of really cool TE generators, Tinker's Construct supports making Flux tools (and as a matter of fact recently ABANDONED IC2 power), PowerSuits can use it as an energy source and for crafting recipes, as can Applied Energistics, and it's even backwards-compatible with anything using BC energy, including Forestry. It's much better suited as a core mod for any pack. The ONLY reason I can see people using IC2 is for UU matter and the induction furnace because of it's speed - and in that regard, the developers of TE are adding upgrades.
Speaking of FTB, I was hoping someone could host a 1.6.4 server (DW20 or Monster pack, I guess Horizons if you feel like it) soon.