What Do Captain Marvel's Skrulls Mean For The MCU?
3. The Kree-Skrull War
Starting with this movie itself, we know that the aliens will be involved in a big way thanks to the Kree-Skrull War forming part of the movie's storyline. One of the defining comics of its era, it's an expansive story that brought together a huge number of characters in a tale of intergalactic warfare.
There won't be many other Marvel heroes involved, and the Vision-Scarlet Witch romance this introduced already exists, so it's going to be a considerably watered down version of the storyline, but an important one nonetheless. It essentially sees the heroes caught in a long-standing intergalactic warfare between the two alien races, with the Skrulls using their shape-shifting abilities to sow unease and paranoia on Earth.
Based on the other images, we can surmise that Carol Danvers is fighting against the Skrulls as part of Starforce - a supergroup formed by the leader of the Kree - while S.H.I.E.L.D. will tackle the problem down on Earth, hence the appearance of Nick Fury.