I assumed he was staying with 1.7.10 for Hexxit since I believe most of the core mods people love in Hexxit have not came out with a 1.8
Also the maker of Arcs is working on there own game or something that wil being using something similar. I think they said the API or something for it is the only public part on it.... There will be someone hopefully willing to come out with some similar to Arcs