Traditional footballing powerhouses Argentina and Germany are also expected to mount strong challenges to the likes of the hosts and Spain , but teams from Africa and Asia have also sprung upsets in recent World Cups . Hosts Brazil kicks off World Cup 2014 against Croatia . Jennifer Lopez sings at opening ceremony . NEW : The U.S. women's soccer team wins gold in London Olympics. Spain is defending champion from 2010 in South Africa .
Hosts Brazil kicks off World Cup 2014 against Croatia . Jennifer Lopez sings at opening ceremony . NEW : The U.S. women's soccer team wins gold in London Olympics. Spain is defending champion from 2010 in South Africa .