Well, it does give Guardians its first connection to Earth, plus one of the stingers possibly hints toward Infinity War, but other than those (rather minor) things and the possibility of some of the weird and insane Marvel shit (fact: James Gunn is a bigger Marvel nerd than you are) being relevant later, it is more or less filler.
It works well as a standalone movie, better as a continuation of the first Guardians of the Galaxy, but it does very little to advance the metaplot. Also, Drax didn't do anything.