To be honest, we don't really know that much about the upcoming new title in the Quake series yet. Since it's announcement last year in June not a lot of information was made public. When the first reveal trailer was shown, it got mixed reactions. On the one hand, it seemed like a very run-off-the-mill, nothing is set in stone yet, kind of cinematic trailer. Sure, one could see the old characters and weapon models getting an overhaul, but in terms of gameplay nothing concrete was shown. What made most of the oldschool players skeptic, were the hinted character specific abilities. On the other hand, the die-hard Quake players were excited and relieved, that in fact there will be coming a new Quake game. Three months later at Quakecon 2016 the first debut gameplay trailer was released. Compared to the first cinematic trailer, one could actually see somewhat tangible gameplay – and it doesn't look bad. It contained everything that one expects from a Quake game: familiar weapons, movement and map structure (arenas). "Pure speed, pure skill, pure FPS!" These seem to be the pillars on which they are going to advertise this new title.

"Pure FPS"
According to the official website the developers are aiming for a game with unlocked framerate, playable at 120Hz while keeping the "classic Quake speed". What this means, is that it is going to be PC exclusive, promising a more refined experience unhindered by possible restriction of a console release. Anyone who has played a FPS game more than just casually is probably most excited about the fact, that the game should run on at least 120 FPS. When it comes to the "classic Quake speed", the developers probably refer to the generally fast gameplay of the former titles, since throughout the history of the series the "gameplay speed" varied quite a bit. In an official youtube video from publisher Bethesda, Tim Willits, Studio Director of id Software, assured the fans that they are trying to preserve "the feeling that [the fans] know and love" from Quake. In general they want the game to be accesible for newer players as well as cater to the world's best players. "We are commited to a long beta phase where we will work closely together with the community and pro players", says Willits. He also explained in an interview with PCGamesN that Quake Champions is going to run on a hybrid engine of Id Tech and Saber Interactive's Saber3D Engine. "We use the id Tech engine to get the feel of the core gameplay right and the Saber Tech for rendering and other elements around that." He also mentions that the business model for the game is not yet decided.

The Champions and eSports
The new feature that Quake Champions brings to the table are – who would have guessed – the so called champions. This newest addition is simultaneously the most controversial, basically splitting the community in half. Tim Willits explains the thought process behind adding champions to the game by saying that seemingly everyone plays Quake in a different style: be it offensively or defensively. In an interview with GamereactorTV Willits explained that the champions are designed to have slightly altered rulesets fitting various playstyles. Combined with new active abilities allow for more depth in gameplay. However at this point it's just speculation about how these champions are going to influence the gameplay.

Quake and eSports
What would a modern multiplayer game be without the eSports component. With Quake, Id Software created one of the first eSports titles – some might even argue the first ever. With the new game coming up, they're planning to expand on their experience and knowledge. We want better spectating, better shoutcasting as well as tournaments, leagues and championships, says Willits.

According to the official Bethesda news site, the game should go into closed beta in 2017.

Bullet points of what we can expect (so far):
    PC exclusive title
    Fast-paced arena shooter
    Classic Quake gameplay (strafe jumping, rocket jumping, air control, weapons etc.)
    Champions with active abilities (and altered rule sets)
    Unlocked framerate (120FPS+)
    Emphasis on eSports, Matchmaking, Leagues
    Long Beta Phase starting in 2017
    Hybrid engine of id Tech and Saber Tech
Feel free to add stuff I forgot in the comment section.