The only thing that will hold them up is Brendan O'Brien's availability. From an interview I heard, Brian is keen to work with him again on their next record and the band had to contact him about studio time. I don't think the means 2015. I also don't think any Brian solo project is in the way. He seems to work on his own between albums. Plus, I think some solo or Molly and the Zombie's songs were being translated or experimented as new gaslight songs. probably not any that have been heard, but that shows where his priority is at right now.
A friend of mine talked to Brian after the Molly show at the Stone Pony and he made it seem like they were just fooling around as a project and no touring was even going to happen. I'd expect this TGA album to come out by the Fall or Christmas time.