I've posted a new update to my CONCACAF coefficients list on my Soccermetrics site. The new season of the Champions League is only a couple of weeks old, but there has already been some movement in the domestic league coefficients.
Mexico has the largest coefficient by a very large margin (almost a factor of 2.5 over the second-best coefficient), but USA has the second highest league coefficient. It doesn't make sense if you go by the performance of MLS teams in last year's Champions League and this year's preliminary round, but Costa Rica's good results in the Champions' Cup have fallen out of the five-year window and USA are still riding the semifinal appearances of Houston and DC United in the final two editions of the Champions' Cup. It's also interesting to find Puerto Rico already ranks third on the domestic coefficient list, but Puerto Rico's "league" is composed of just one team --- the Islanders. That coefficient would likely diminish if teams from the PRSL find their way into the Champions League qualifying round.
There's a long way to go in the Champions League, so these coefficients will change.