We already knew that Sylvester Stallone's new role involved armor of some kind and that he had already started filming, but now we know what part he will be playing.
Stallone will be featured as one of Yondu's Ravagers in Guardians Of The Galaxy Vol. 2, and has a few scenes already completed. No other information, like his name and purpose, is known at this time, but with the casting of Stallone, it looks like the Ravagers might play a bigger role in the new film than they did in Guardians of the Galaxy Vol. 1.
Stallone will follow up his fantastic performance in last years Creed with a Marvel Universe debut, and I'm looking forward to seeing how he fits into the overall puzzle.