3.9.0 will be bringing more than just a new league, it will be totally overhauling the endgame, and how we engage with the atlas, as well as tons of new things for bow builds.
The core 3.9.0 expansion is Conquerors of the Atlas, which pits us against exiles much like ourselves, who lost themselves to the endless grind, and were trapped by Zana in the Atlas. We will have to fight them to enhance our own Atlas, and the Atlas itself is being entirely overhauled. We will be able to upgrade our maps, to the point where you could optionally run nothing but tier 14-16 maps, if you dedicate yourself to it, and choose to do so. It is expected that you will be running up against the Atlas Conquerors roughly every six maps. The goal of this is to increase the difficulty and replayability of the endgame, and to make new items have value, especially with the Support Gem Plus system.
Support gem plus will add new gems, that pick up from where level 20 support gems stop, and add new functionality to them. Fork Plus, for example, adds a second fork to your supported skills, allowing for a downright ludicrous number of projectiles spawning from even a single main projectile.
For bows, we are getting an overhaul of Ranged Attack Totems, now Ballistas, and they will maintain functionality with wands. There are a pair of new support gems we know about, one that turns all your skills to a Barrage-style attack, and one to turn them into a rain, firing them in a nova from further away.
Metamorph league, releasing alongside the 3.9.0 launch, will allow for quality to be applied to accessories, bosses to be morphed together, and will be a dangerous source of content without requiring much time in each map. You can kill unique monsters in each zone, and eventually combine them all together into a gooey, morphing, unspeakable horror, which our allied NPC this league looks to investigate with the goal of discovering what makes them tick, and what has brought about his own internal violence. Similar to the recent league, you will be able to see what rewards are coming off each of your metamorphs via a variety of symbols.
In Metamorph league, a variety of quality types are available, that can improve different types of modifiers, such as life, resistance, or caster mods. In addition to increasing stats, it also improves the odds of acquiring the mods that are related to your quality stat. This is a great new method of crafting high end item, offering some great options for dedicated crafters.
Check out the trailers for both the Metamorph and Conquerors of the Atlas expansions here!