Trion Worlds just released the official preview page for Rift Update 1.4: Legacy of the Fallen. While the page lists all of the patch's features, it says simply that the update will be "coming soon." Here's a summary of the upcoming content:

RIFT 1.4 - Coming Soon

Some among the Ascended believed when one of the Blood Storm fell, that dragon’s cult would shatter from the blow. Greenscale is slain and Akylios sunk, yet House Aelfwar and the Abyssal continue to plot and scheme. Now the Ascended must overcome both groups of desperate cultists and their rivals in the opposite faction in RIFT 1.4: Legacy of the Fallen.

After their deaths, the vanquished dragons’ essences exploded into elemental energy. Now their cultists strive to claim the Dragon Mote fallout scattered throughout Telara. The Guardians and Defiant must race to harvest these motes for themselves lest the Abyssal or House Aelfwar reclaim the power of their fallen masters.

The Water Saga

To combat the Abyssal, Ascended can embark on the Water Saga, an epic quest series that unravels the origin of this lunatic cult. Guardians and Defiant must stop the Abyssal resurgence, save important members of their faction from the cult’s insanity, and learn more about the sinister Tidelords, the heroes who first imprisoned Akylios, and the Faceless Man’s secret past. Aimed at high-level Ascended acting alone and in groups, the Water Saga offers both epic loot and a swift and cold-blooded Crocnard Mount.

Drowned Halls

The Abyssal threat looms large in Drowned Halls, a terrifying sliver in Scarwood where Akylios has conquered Telara. The Ascended must enter this alternate dimension and stop the faceless sorceress Hydriss from leading her forces into other timelines. This 10-player sliver offers rich rewards and terrible dangers to any Guardians and Defiant who brave its apocalyptic events.

Escalation of hostilities

As the Cults of Water and Life rail at their gods’ demise, tensions rise between the Ascended factions. Soon, Defiant and Guardians will clash in the open world combat offered by PvP Rifts. On top of Capture-the-Flag, the Warfront of Whitefall Steppes will feature an alternate “Escalation” mission where combatants must race to charge their side’s cannon with sourcestone shards issuing from an Air Rift. Every week, strategic focus will shift between Warfronts, and completing the week’s featured Warfront will earn Ascended greater rewards.

LFG leaps across shards

To ensure you get into groups and dungeons faster, the Looking for Group system now works across multiple Shards, swiftly recruiting Ascended to join your quest.