According to statement released by Vikings, the Exempt/Commissioner's List requires that Adrian Peterson "remain away from all team activities... until the legal proceedings are resolved." His court date isn't expected to be until 2015, meaning he could be out for the season.
Peterson is unlikely to have his legal situation figured out until sometime next year,
meaning he's also unlikely to play for the rest of this year. Don't drop him yet, but prepare for it emotionally -- he was your first-round pick, after all. Matt Asiata and rookie Jerick McKinnon are expected to pick up the load if AP is in fact out for the season