I would love to see red and yellow cards in football. Just imagine that in the 4th quarter of the Superbowl the Steelers offense has 11 players to the Dallas defense's 10. Talk about adding some more flavor to the game.
That said, soccer is a gigantic snoozefest. So what if they are in great condition. So are joggers and I don't watch them either. As a matter of fact, I would rather watch golf than soccer and I don't like golf.
When baseball got a little too defensive the mound was dropped a couple of inches to aid the batters, the ball was juiced up a bit (oops, not supposed to mention that) and the players were juiced up more than a bit (oops, really not supposed to mention that). The rules of soccer need to change to get out of the nil-nil doldrums it seems to be in.