Actor Aaron Douglas (Galen Tyrol) was recently on Cort and Fatboy of KUFO, and revealed massive spoilers for season 4.5. (Though he seems to think he was talking about the ending of the midseason finale for 4.0 Revelations. Instead, it seems that he was talking about the first ep of 4.5, Sometimes a Great Notion.) While confusing, it does appear that the thrust Aaron's comments are basically accurate.
However, SyFy Portal attempts to clarify some of the confusion surrounding Aaron's comments and adds some details from unnamed sources.
Don't read any of the above linked articles if you want to remain spoiler free about the rest of the series.
It'll be interesting to see if TPTB have a talk with Aaron about his Non-disclosure agreement.