Following the recent announcement of Stellaris: Utopia, the team deemed it necessary to outline how Psionics would be changing with its launch.
Published through a fairly lengthy Developer Diary, Wiz - the game's director - outlined how these changes would apply to both those who pick up the Utopia expansion at launch and for those who do not.
For the most part, things will barely change for people running the free version of the game. While there'll be a few tweaks detailing how to travel down the Psionic route, the vast majority of the changes and additional perks will be present in the expansion build only. For free users, the only major change coming into play is how you go about initialising the path to Psionic enlightenment. Rather the researching individual technologies, only those focusing on their efforts as a Spiritualist Empire can travel the road - though you can choose to do so at any point in the game.
For those with the expansion, however, the Psionic route will take a drastic turn. These features will no longer be present within the standard Technology tree. Only the initial 'Psionic Theory' trait will be available through there with the rest appearing once you pick up the 'Mind Over Matter' Ascension Perk. One you've travelled far enough down that path, your species' newly awoken powers will alert them to the existence of 'The Shroud' which should make for some enlightining - if not expensive - trips into the void.
The official blog post goes into far greater detail, but the developers are, understandably, leaving details of The Shroud under wraps. People need a little excitement in their lives right now.