The 500 Euro note will be a big hit with drug dealers and gangsters!
500 Euro note
It's suddenly one of the biggest banknotes in public circulation (I don't believe the $500 US is publically circulated) in the world, thus a favored currency for shady cash deals!
On the positive side, it appears that a majority in the UK now believe that the Euro is inevitable there too someday. That's when the Euro will truly become a success - if and when the UK joins.