Although I don't have an issue with 'Redskins', having been born and raised, and lived most of my 52 years here, I've thought a day like this might eventually come, and I've tried several times to come up with something that would honor Native Americans while modifying as little as possible that fell outside the realm of the nickname.
It's really tough, though, given the names of the tribes who occupied the Chesapeake Bay watershed prior to the arrival of folks from overseas...
http://www.ala.org/aboutala/indigenous-tribes-washington-dc
Reading that, 'Anacostans' seems appropriate.
From a business sense, doing something to honor Native Americans, and tie the team to raising awareness and involvement in issues involving them, would be nothing but a massive, massive win.