Grinding Gear Games pushed v0.5.0 for Path of Exile 2 early access and this is a pretty significant one. The new Ascendancy class for the Mercenary was added, giving crossbow users a much-needed power spike in the endgame. They also reworked how armour mitigation scales at higher levels because characters were hitting a wall around level 75 where physical damage just destroyed you.
The endgame mapping system received a new tier of content called Corrupted Atlases, which are basically juiced-up versions of existing maps with modifiers that stack in interesting ways. Loot tables were adjusted so rare currency drops are slightly more common in these maps.
There was a major server-side fix for the desync issues that plagued melee builds. Hit detection should feel much more responsive now, especially for the Monk class.
Trainer update -- we are still investigating compatibility with v0.5.0. The game uses a new anti-tamper check on startup that we need to work around. If you try to use the old trainer version it will likely crash on launch. Please wait for the updated trainer before playing with cheats. We will post an update in the forums once the new version is ready. ETA is roughly 48 hours.