Ronan and Korath haven’t been given much screen time outside of the first Guardians film so it would be great to find out what motivated them. The Kree-Skrull war might be connected to Ronan’s hatred with Xandar, so there is a lot of history that could be explored here.
The most interesting aspect will be how they avoid the film from contradicting Agents of S.H.I.E.L.D. as according to the series Coulson never met a Kree before. Either he only has a very small role throughout the film or he is replaced with a Kree and misses out most of the events. Fans of the show also hope for another veteran S.H.I.E.L.D. agent to return as Melinda May was a part of Coulson’s past.
This might be Marvel Studios best chance to include characters from the show to truly prove that everything is connected. It also opens up the question if we can expect a few cameos by Peggy Carter, Howard Stark or Hank Pym, who have a storied history with the organization.
Who do you want to see return? What cameo are you hoping for the most?