The first proper expansion for Stellaris [official site] will launch on April 6th, Paradox announced today. Utopia adds shiny futuristic features like buildable Dyson spheres, ring worlds, and habitat stations (very utopian), psionic, biological, and mechanical 'Ascension' paths (also utopian), and a variety of new ways to oppress and enslave other races (very... Omelasian). Well, utopias are always meant to be rhetorical, aren't they? While Utopia is a paid expansion, the big update 'Banks' will launch for free alongside it with a load of handy new features.
I've gone over a lot of features of Banks and utopia before so let's do this quickly.
Along with adding fancy things like Dyson spheres, which are vast structures surrounding entire suns to capture their energy, Utopia will introduce endgame paths through Ascension perks to determine the future of your species, and expand Slavery and Purge policies so you can do awful new things to subjugated species. This recent dev diary gets more into the new megastructures, this one gabs about indoctrinating primitive cultures, and this looks at Psionic ascension, and here you can read about hive minds and new civics options. Previous diaries have gone over the rest.
Like many Paradox expansions, Utopia has many more interesting little features and bits than its name and supposed theme would suggest.
The Banks update, meanwhile, will bring features like Tradition trees with perks for different playstyles, options for per-species rights across your empire, and an overhaul of the Factions system to make represent all sorts of groups, and more.
Utopia is coming to Steam at £14.99/$19.99/€19.99, which is a couple quid more than Paradox strategy expansions tend to cost. The most expensive Crusader Kings II add-ons, for example, cost £10.99. Stellaris is all 3D and that, mind.