Woudnt really agree Sweden is a "dark horse candidate for this WC", thats really stretching it. However, its a very good team this year, if Zlatan plays or not. Its really not in the details.
People saying Italy was horrible havent really been paying attention to what team they played. Even tonight at San Siro, Sweden really rumbled them the first few minutes, and where rock solid after that. It was a much, much shorter time of pressure than the first game, but that little time of extreme pressure has so much impact when you make zero misstakes the rest of the game. The opponents never get a chance to get comfortable (even though they actually did for a few minutes late first half this game, same as France did late second half a few months back).
I seriously havent seen this kind of team performance since the best days of 2000-Barcelona. When they pressure buildup early in the game, they are like ants, telepathic. Sure, then they get tired much quicker than that Barcelona squad ever did, but then they have already set a perfect frame for the game. As long as they dont fumble, the opponent team will never really get into it after that.
Or well, regarding details, if there is one little detail this Sweden cant really do without its Forsberg. Even when he is not the best player on the field (which he normaly is) he is still the X factor that prevents the team from ever becoming easy to read. He covers 8/10 of the field and within that really has no short comings.