Marvel is preparing to introduce a new team of cosmic heroes called the Asgardians of the Galaxy. The team appears to be the replacement for the Guardians of the Galaxy, whose comic book series ended in January of 2018.
Guardians of the Galaxy writer Gerry Duggan announced on Twitter that the Guardians series would end after issue #150 in January, even though #151 was included in Marvel's February 2018 solicits. The plan was for their story to continue in Marvel's epic Infinity Countdown, a crossover event that also features Adam Warlock, Black Widow, Captain Marvel, Daredevil, Darkhawk, Silver Surfer, and Ultron. Following the conclusion of Infinity Countdown, Marvel Comics will launch the next part of the story, Infinity Wars.
Marvel Comics has released a teaser that reveals the "Guardians of the Galaxy are no more" and asks the question: "Who are the Asgardians of the Galaxy?" One major takeaway from this teaser is that Marvel may not be planning on bringing back the Guardians of the Galaxy series anytime soon.
Some fans believed that Marvel would relaunch the series at the end of Infinity Countdown or Infinity Wars. While we can assume the team will have their own title again at least in time for the new Guardians of the Galaxy movie in 2020, this news does suggest that the Guardians relaunch isn't happening this year.
As for how Marvel will conclude their story... the details are hard to come by. Drax has already quit the Guardians, and Groot's changed since he learned to speak. More changes may be coming as Infinity Countdown continues, but it now seems that the events of the two major crossover will cause the team to completely dissolve - permanently.
It remains to be seen who will replace the Guardians. As the name "Asgardians of the Galaxy" is quite specific, this narrows down the list of possible team members to a relatively small number, as opposed to the wide range of heroes who have served with Star-Lord's Guardians. Among the characters who could join the Asgardian team include the Warriors Three, Valkyrie, Lady Sif, Balder the Brave, Loki, Enchantress, and Thor's sister, Angela.
Since Thor: Ragnarok's Valkyrie is a separate character from the original Valkyrie in the Marvel Universe, she too could join the group. Thor could possibly serve as leader, despite the fact that the character is already a member of the current lineup of Avengers. If not, a comic book starring a team of Asgardians could be a fun way to showcase other prominent Asgardians aside from the God of Thunder.