We've been working on the 1.6.4 versions of HappyDiggers AMP and RPG for months now. They are nearly ready.

Unfortunately the FTB client isn't. They tweeted that they'll have a way for third party mod packs (that's us) to update their mods on the launcher in a few days. So I guess we'll just have to wait and see.

In case anyone missed it, here you can read why the new FTB client is taking so long:
Why no new launcher.