Brazil - 20 appearances, champions (1958, 1962, 1970, 1994, 2002)
Croatia - 4 appearances, third place 1998
Mexico - 14 appearances, quarterfinals (1970, 1986)
Cameroon - 7 appearances, quarterfinals (1990)
Given the histories of these sides (and where the tournament is being held) Brazil can be written in ink as the winners of the group. They are rock solid at the back with the Paris -St. Germain man Thiago Silva and David Luiz of Chelsea pairing. They have arguably the best right back in the world in Dani Alves of Barcelona, and his running mate on the left Marcelo of Real Madrid could make the same claim. Their attacking force in 2014 doesn't quite compare to the legends of Brazil's past, and they can't hold a candle to the holy trinity (Ronaldo, Rivaldo, and Ronaldinho) that brought them glory in 2002. That being said with that defense they don't need to be overwhelming up front. In truth this team is more like the 1994 winners who played a pragmatic brand of soccer that brought home a trophy, but not adulation back home.
If it weren't for the presence of the live wire that is Neymar, who lit up the Confederations Cup with his performance, this Brazil side would be considered downright staid. Hulk (So named because he looks exactly like Lou Ferrigno would if Lou Ferrigno played soccer), Fred, and Oscar are great players, but they aren't likely to be remembered as immortals in the way that other attacking players (Garrincha, Jairzinho, Rivellino, Eder) for Brazil winners have been. But then again this is not a team that needs to overwhelm teams with the beauty and efficiency of their attack. This is not 1982.* If Brazil is to win and put a 6th star above their crest they will do it with great defense and timely offense.
The only other question for this group is who joins the hosts in the knockout stages against the group A winner, presumably Spain. Croatia is the favorite in the eyes of many, and its not difficult to see why. They have perhaps the best non Brazillian player in the group in Real Madrid's brilliant midfielder Luca Modric; A phenomenal running mate for Modric in Ivan Rakitic and plenty of options up top.
For what its worth they also have a Brazillian on their side in Shakhtar Donetsk's Eduardo, a naturalized Croat who was born in Rio de Janerio. Eduardo is one of several options up top for a Croatian side that doesn't lack for punch. The best of the bunch is Bayern Munich's Mario Mandzukic, who will be suspended for the opener against Brazil thanks to an unnecessary red card picked up in the playoff with Iceland. The biggest question mark for the Croats is their slow, arguably ponderous defense. This is perhaps not the best group to have a defense that is lacking speed. The Mexican's, Brazilians and Indomitable Lions of Cameroon have no shortage of speed in their sides. All of them will be capable of catching them with a sucker punch goal on the counter, and they could be their undoing.
If its not Croatia advancing on it will probably be the Mexican's. Yes the Mexicans disgraced themselves in qualifying and generally looked incompetent in the Hex, CONCACAF's final qualifying stage. El Tri manage to so thoroughly disgrace themselves in 2013 that I almost started to feel bad for them. But then I looked at Rafa Marquez's eminatably punchable face and was cured of such namby pamby softness.
El Tri will have a chance in this group because they are suddenly and inexplicably playing with confidence and ambition in attack after abandoning both concepts so completely in 2013 that they scarcely resembled the CONCACAF devouring giants they briefly were for about 18th months from the 2011 gold cup through the Olympics. The bad news for El Tri fans is that they are hilariously ill equipped in defense. Still they have enough attacking quality to pose some problems for Croatia in what will likely be the 2nd place deciding game.
As for Cameroon, the most historically significant African squad in the world cup, this is going to be a bumpy ride. They have some name brands on the squad; Barcelona's Alex Song, Chelsea pariah* Samuel Eto'o. But they had a Mexico like struggle in qualification from CAF and haven't come out on the other side looking better. This World Cup will not go well for them, but they will always have Roger Mila, so thats not nothing.
*Really everyone's pariah at this point
Predicted Order Of Finish