Good news... (or about the closest approximation of which that can be found in such cases.)
Checking online I see that, as of February 27th, 2014 there is a new decision in Mexico for my son's Hague case (which started in 2008.)
At this point I'd have to create a flow chart to describe the way my son's Hague case has traveled through the Mexican courts (which would have arrows showing it bouncing around not unlike a ball in an arcade's pinball machine) but, suffice it to say, yet another Mexican Federal Court has overturned the two previous State court decisions denying my son's return to the USA and, presumably, ordered my son be returned home... again.
Since this is Mexico, and the United States Central Authority on the Hague Convention is staffed by monkeys on typewriters, what this decision actually means in practice is anything but clear, but I'd hazard to guess it does not mean my son is coming home any time soon (so much for Special Advisor Jacobs' much vaunted progress and compliance out of Mexico.)
Typically I can find a full copy of the decision online with the names redacted but I have been unable to do so thus far.
I could pay a lawyer to go to court and get me a copy of the full decision, or request the Office of Children's Issues obtain me a copy as they are required to do under international law, but since I've never received copies of decisions I've requested from them that were issued 5+ years ago though I think I'll just save myself the time and frustration of asking the monkey brigade to do anything.