Once you beat LEGO Marvel's Avengers, you'll be greeted with this little sight. Oh, what's that? That sure looks like Peter Quill's aka Starlords Walkman and headphones.
Traveller's Tales is notorious for teasing their next project. LEGO Batman 3 had Dinosaurs at the end, LEGO Jurassic World teased Dimensions, etc. So seeing Peter Quill's Walkman and headphones is certainly enough of an indicator. However, I'm not sure if I believe that it would be TT's next game. After all, they tend to tackle various licenses, and doing another Marvel game right after they've just completed one doesn't seem in-character for them.
That being said, it will be great to see Guardians of the Galaxy play a major role as the next Marvel LEGO game, especially since they're considered to be a part of the Marvel Cinematic Universe. And considering that characters like Starlord was already available in the previous game, Marvel Super Heroes, it wouldn't be much of a stretch to think they'll be making a big comeback.
Plus let's not forget that Guardians of the Galaxy Vol. 2 is hitting theaters in May of next year. It would only make sense that TT Games capitalize on the hype.
Also, make sure to check out our review, if you want to know what's new about this particular LEGO entry.