The new rule that gives a yellow card for diving seems good. I'm German, and when I saw 2 German players get carded for diving in the first game I thought "Fair enough. It's sucks it's against my team, but I like that they're doing something against it this year." I think that's a good way to deter players from diving. But since that game, I haven't seen any yellow cards given for diving, and I've seen a lot of blatant dives. Especially from Italy. The rule is a good one, but it's not going to work if they don't enforce it. Players will continue to do it as long as the rewards outweigh the risks.
I'm against the idea of instant replay in soccer. I love that the action doesn't stop and part of the fun of watching the world cup is all the drama around calls. I see the benefit to instant replay, but it's a slippery slope that ultimately leads to the game being drawn out and made to be more boring.
Not having instant replay also teaches an important lesson for people watching. LIFE ISN'T FAIR. Sometimes you catch a break. Other times you get hosed. That's life. Don't cry about it. And don't expect a ref to be sitting there making sure everything is fair all the time. The best thing you can do is to prepare better next time and work harder next time, so that hopefully you're not at the mercy of breaks that can go either way. American sports have been hurt by this obsession with getting calls right. People rely on everything being fair. It's a cop out to say you lost a game because of a bad call. Notice the USA fans that cry about the bad call that cost them a goal and thus, the game. Here's a different perspective. Had they not played like crap the first half, and gone down by 2, they would have won, regardless of that bad call.