Nick Cole and Jason Anspach are doing will with their not-Star Wars series right now. There are others--myself included--who also decided to fork George's revival of the pulp tradition, but I can already tell you that what they decided to emphasize and what I picked are not the same things. The result will be very different stories, even if you can see where we're coming from and building upon.
The point? Don't fear building off the same set of sources. You don't even have to see this in literature; a simple viewing of any given episode of Iron Chef will be plenty sufficient to demonstrate that point. Go ahead, write your own not-Star Wars. Show us what you've got. It's not going to be what Nick & Jason do, or what I do, or anyone else. Maybe you like focusing on the underworld, the rogues, and the bounty hunters. Maybe you love the romance, the fleet battles, knights and princesses. Maybe you want to get with the grunts, the fireteams, and the soldier-eye-view of things. Whatever it is, write it and bring it.
Don't worry about if it's as good as another's. You'll get better with practice; E.E. Smith didn't begin his writing career as the legend that wrote Galactic Patrol, and George did films before Star Wars, so don't sweat it. Next time that a Call For Submissions gets posted--here, or where one of our friends' post--read it and go for it. The worst that will happen is that they will pass, and everyone collections rejection slips early on; it comes with the territory.
Just do it. Just create. The audience is waiting for good, earnest storytelling. You'll get the help you need along the way, so just do it and don't worry about it.