It's Update 14! Read more at https://forums.warframe.com/index.php?/topic/263213-update-14-the-mad-cephalon/

Highlights:

• New User Experience 2.0 - New Prologue, new Tutorial, much more improved matchmaking system, replaced Loki as starting Warframe with Volt once again (LIKE THE GOOD OLD DAYS! WOOHOO!), and added beginner mods to players doing the tutorial.
• Quest System - Vor's Prize as the debut quest (FINALLY), new Warframe, Mirage, obtainable through quests, as well as the Kubrow and Genetic Foundry.
• Player Ship - Introduces Ordis, the Liset's Cephalon (ship AI, so to speak), the Liset provides access to basically everything through contextual devices via the ship - unlocked through Vor's Prize.
• Diagetic UI - In missions, press ESC to call up a new UI in the palm of your hand. You can see all mission details, including current pickups and mission progress. In the Dojo, it allows for easier decoration placement/editing.
• Genetic Foundry & Kubrow - Kill Kubrow, obtain Kubrow. Kubrow personality types, this is Pokemon in Space.
• New Warframe: Mirage, Master of Illusion - If it’s Mirage you seek, you may obtain by Quest. To her powers of illusion we can attest. Within a vault, the requirements lie, as part of a dark and corrupted infested sky. We know via RedText that she can create 5 clones of herself. Sounds amazing.
• Infested Eris - The Infested have reclaimed Eris. Gamemodes include: Hive Sabotage, Exterminate, and Survival.
• Weapons - AkZani, fast firing dual pistols. Silva & Aegis, fiery sword and shield combo - comes with new stance, "Eleventh Storm."
• Dark Sectors Enhanced (THE ONLY PART PEOPLE GIVE A FUCK ABOUT) - New Dark Sectors Conflict has arrived! A new gameplay mode has arrived to replace the existing Solar Rails Conflict missions. Choose which Clan or Alliance you wish to support and play the role of Attacker or Defender on a multi-staged objective mission. Up to 4 human players per side, with empty player slots auto-filled by Spectres. Rank up your mods while you play! Are you a Clan or Alliance Tacticition? Find the new SCHEMA customization area in your Orokin Lab today! Using SCHEMAs, you can customize your Clan or Alliance’s Solar Rails by selecting room orders, placing turrets and Specter spawn points! Clan and Alliance members can enter your SCHEMA and contribute to your plans! Applying your SCHEMA to rails not in a Conflict state to have them ready for the next Conflict! Battle Pay is now proportionate to your contributions to the mission. For the new game mode, Attackers have to destroy the "core", and defenders have to prevent that. The more damage you do (or prevent, as appropriate), the more you get paid.

Note: Editing to add the "Highlights" and all the cool stuff in it done by Supplice, just because it's needed. Too lazy to make it as good as my previous one on U13 because well.... games.