I actually don't see Brazil going further on this tournament. They are broken as team but with too many nice players. In other hand, Argentina have a solid national team and willing to revalidate their title.
Well, but football can have surprises but this is my view
Nothing tells me Brazil will win but anything is possible. Young talents, years of suffering from being relegated to places they don't deserve can count as motivation but isn't enough as Messi and company are strong team.