I think that they're just waiting on Mystcraft at the moment. Unfortunately, the update broke Mystcraft, so we'll need to wait for Forge to update first. I think XCompWiz's pull request has gone through*, so it shouldn't be too long.
Ok guys once again. FTB BETA pack A will most likely not be updated ever. It was a test pack, The 1.4.6 packs will be Magic World, Mind Crack, Ultimate, DirePack, Possibly Universal Electricity, and the Tech Pack. There is no "Main" pack
True. I assumed he was talking about Ultimate/Magic World/Tech, as opposed to third party packs like UE or commissioned packs like Direwolf20 and Mindcrack.