Here's a summary of the main changes in DOFUS 2.8:

More than a quest, a major part of the game is making its entrance with this update! Reveal the Meridia’s story day by day, benefit from their effects and make offerings to them in order to win prizes! Background and role-play lovers or hardcore collectors, regular or casual players all can find what they’re looking for in the Almanax!
[More information in the devblog]

Every day in the Temple of Scriptures (AKA the Almanax sanctuary), Antyklime Ax will offer you a unique and simple quest! Get your hands on the resource or item desired by the Meridia of the day and offer it to them! As thanks for your devotion, the Meridia will give you experience and Kamas, but even better than that, you’ll also get Almokens and calendar pages that will allow you to purchase numerous prizes… and a new Dofus!
[More information in the devblog]

The Meridia are minor gods assigned to each day of the calendar of the World of Twelve, and they’re getting more and more important! Starting on the day of the DOFUS 2.8 update, every day of the year will get its own bonus. Monsters will give more experience, resources respawn faster, or there could even be special items dropped in some particular zones…. Get ready to discover and enjoy these 365 daily bonuses!
[More information in the devblog]

Al Howin’s curse will evolve this year! A new dungeon will appear near the Evil Forest, and there will be new prizes for those who are capable of unlocking them. This content won’t be available on the day of the 2.8 update, but only during the Al Howin event near the end of October.

The Client Development Team has penned a digital love letter to players who can’t stop multitasking while Dofusing! The new alert system allows you choose to have notifications sent to your screen as soon as something important happens in the game. This is especially good for multi-accounters in case you’re not looking at the right window when stuff is going down (e.g., someone attacked you, one of your perceptors is being attacked, a Kolizeum battle has been found, a player is inviting you to their group, etc).
[More information in the devblog]

As in version 2.7, many interfaces have been improved for the 2.8 update. Of special note are the changes made to the soulstone market to make it less awkward, the ability to move the timeline during a battle, and the integration of equippable items to the shortcut bar.
[More information in the devblog]

The Iop class has been adjusted in this update. Several spells with effects that were too similar have been replaced by new spells to give Iops more tactical and stimulating gameplay. While they are still one of the biggest damage dealers in the game, the Iop class can now call upon a more varied and original array of spells.
[More information in the devblog]