Yes, the new 1.6 version of the Direwolf20 FTB pack is coming. It will be out in the next day or two. No, a 1.5 DW20 world is NOT upgradeable. The FTB crew has explicitly stated that 1.5 worlds are not compatible with 1.6 FTB at all. What does this mean for Serenity? Well, that's a really good question. I know that there are people in the midst of big projects, so I suspect that we won't be changing anything on the server any time soon. Eventually, we'll want to upgrade or try a new pack, but I think that that's still down the road a way.