The structure as parsed by USSoccerPlayers.com is this:
The six lowest ranked nations play off against each other, leaving three standing and reducing the total field to thirty-two teams.
From here, groups kick in, with the thirty-two teams drawn into eight groups of four. The two top teams from each group advance. Those sixteen teams are drawn into four groups of four, again with the top two teams in each group advancing. The final eight teams play in two groups of four, with the winner of each group automatically qualifying. If CONCACAF receives a fourth World Cup spot, then the second place finishers will also qualify. If not, the two runners-up will play off to determine the third qualifier, with the loser going on to play for a spot against a team from another confederation.
The total number of games for the top thirty-two teams, not including any needed play offs after the final round, is eighteen. That's the same number of games as in the previous set up.
Seeding will play a major role in this process because of the final round moving to two groups. If the United States and Mexico are the top ranked teams in the region, does that guarantee that they will be drawn in different groups? If CONCACAF does not use rankings in the final round and draws teams together randomly, a possible group with the US and Mexico together would unbalance qualification significantly; add in the possibility of the second place finisher in such a group having to play off against a nation from another region just to qualify, and things could get very interesting.
Keep in mind that if seeding is used throughout, and the US and Mexico are not drawn into the same final round group, they could both qualify without ever having to play each other.
*UPDATE*
I'm moving Jason Kuenle's comment into the post because it provide a likely reason for why CONCACAF is changing things:
My guess is this has to do with two things; money and rankings. While the number of games played by the top teams will not change from 18, the number of games played by lesser CONCACAF teams will go up, in some cases dramatically. Matches for these second tier teams obviously bring in revenue, but they also should increase the FIFA rankings for those CONCACAF teams.
Take Jamaica - last cycle they played 8 matches, two against Bahamas in the second round and then in the group, two against each of Mexico, Honduras, and Canada. They totaled 5 wins, 1 draw, and 2 loses. Under the new system, they would be in Pot A, and play against a Pot B team like Haiti, Guatemala, or Cuba, a Pot C team like Suriname, Puerto Rico, or Belize, and a Pot D team like Bahamas or Aruba. They should move out of this group with a record of around 4-1-1. They would then move to a group that looked similar to the Mexico, Honduras, Canada group, where they went 3-1-2. Even if they did not make the final groups, they would have played 4 additional matches, including two home gates for the federation. An additional two teams making the final round gives even more chances to play all 18 matches.
Matches played in 2010:
20 - 1 team
18 - 5 teams
10 - 1 team
8 - 5 teams
4 - 9 teams
2 - 14 teams
Total matches played - 112
Under the new rules:
18 - 8 teams
12 - 8 teams
8 - 3 teams
6 - 5 teams
2 - 3 teams
Total matches played - 150
Because World Cup qualifier matches have a 2.5 multiplier on them compared to friendlies, more qualifiers means more points, which means a higher ranking for midlevel teams. It's akin to fattening these teams up as a sacrfice when they play the US and Mexico. The US and Mexico have been just on the outside of being seeded for the last several world cups. The new qualification route means avoiding loses to each other while increasing the points gained by beating other teams. Also, the new qualification procedure takes advantage of the new confederation rankings giving CONCACAF a slight edge over AFC and CAF.
It is sad that there will no longer be a "winner" of the qualification and that we may not face Mexico in qualifying, but it's a good move by CONCACAF. The mid-tier nations need to be the backbone on which CONCACAF grows. Getting those federations a greater number of competitive matches and more money (if it's not wasted or embezzled) will help the US in the long run.
