If the FIFA has a simple system in place, then it will be good. What I don't want is fans getting their travel plans cancelled at the last minute, because the American embassy will not issue them a tourist visa. I know how hard it is to get a tourist visa for the United States, and I have seen multiple occasions of visa applications getting rejected after many months of waiting. I don't know much about the visa requirements for Canada and Mexico, but I guess the situation is much better that what they have in the United States.
The USA visa problem is well known and I'm sure FIFA is well aware of that. I don't know how will they work it out but it's definitely unacceptable that someone has to wait visa for several months and then purchase a ticket for the World Cup.