Funny thing is, I just had the opposite problem. The launcher downloaded all the mods, but failed to download minecraft and hung in a half-done state. After a couple of tries starting from the feed the beast launcher, I navigated to the folder to find it completely empty save for the Mods and Config folders. I've deleted the install and I'm trying again from scratch.
Edit: I've just finished re-downloading it, and it's hanging again. The normal Popup where it downloads minecraft is not present, and the Console window spit out this(not sure if it's relevant):
debug: retaining modpack file: C:\Users\Hivemind\AppData\Roaming\ftblauncher\ModPacks\Direwolf20_1_6_4\Direwolf20.zip
I've got to go make dinner, I'll check back when I'm done to see if anything changed.
Addendum: The Second Install worked. Took well over a hour to just get the second part of the installation done, but it's fixed and runs. Yay for heavy traffic!