True, and the new design is better than the old because of it. But it hasn't resolved the issue enough to really matter. Some less subtle physical difference is required -- put a hole in it, make it an obviously unique size, whatever.

At least that's how it seems to me. It's an interesting design issue. I don't personally care too much -- I'm fine with the paper bill -- but I do have curiosity about why the coin designers have made the decisions they did about the $1 coin.