AFAIK, it was said, that the power armors will be available to the highest-ranked characters in the factions someday, after completing the bunch of quests and really proving its loyalty. Also, there will be a couple of new armors after update (along with some changes in existing ones), such as the Enclave combat armor, that will have a slightly better stats (with some downsides) than combat armor, and the Brotherhood armor will have opposite downsides, but its own upsides. I advise you to use the search function next time and look closer for what's developers are saying.