Okay, so with Group B where it stands now, I believe that Greece, while winning today are still out of it. The Argentinians should beat the Greeks, and thus putting them at a very low score differential (-3,-4 perhaps, they are at -1 now). Thus it will come down to the Nigeria (0 points -2 Goal Differential) vs. South Korea (3 Points -1 Goal Differential). If the game ends in a draw the Koreans will go on. If Nigeria wins, they will go on, and obviously if Korea wins they go on. Does anybody see flaw with this. The Greeks could throw a big wrench into the whole thing if they tie Argentina though. Only time shall tell.
Edit: Group A is similar. If France kills South Africa, and Uruguay or Mexico loses to the other it would be possible for France to sneak into second place. We shall see what happens though.