It's so tempting to say "let's wait and see" when you have potential breakout guys like Miller. But if you go back and watch his snaps from last year - the vision, the feet, the cutback ability at the line of scrimmage, his "narrowness" when he hits the hole, the acceleration when he plants his foot, the downfield elusiveness - it's impossible for me to just take the conservative view that he's proven nothing so far.
Factor in the supposed added strength, speed and understanding of the playbook - together with the influence of Gore - it's kind of mindblowing what this kid might do. The idea his footwork is BETTER than it was is frankly scary. Health is always the concern for a runningback, but history tells us that injury record (good or bad) doesn't guarantee future health.
This kid's ability is way too exciting to file him in the "pending" tray. I foresee a very special run game this coming season.