Yeah. So far I have a lot of RedPower 2 working, Equivalent Exchange 2 somewhat, BuildCraft 2 somewhat, IndustrialCraft 2 loads but the energy net doesn't seem to work, Thaumcraft 2 loads but still lots of crashes and rendering problems, and Nether Ores even though the worldgen doesn't work. But with no GUI support yet it's hard to know what else works/doesn't work. But it's coming along fairly well so far, all things considered.
Man that's a lot of 2s, now that I think about it. RP2, EE2, BC2, IC2, TC2.
Seeing a port of the original FTB map would be fun.