Actually, there was something pretty juicy in the WikiLeaks from Mexico: Guillermo Galván evidently suggested the imposition of martial law in Mexico in 2009, a proposal that was subsequently shot down by Fernando Gómez Mont (martial law would require Congressional approval to be legal, and Gómez Mont, as the Interior Secretary, acted as Calderón's chief liaison with Congress at that point). Had it been implemented, Galván's gambit could have resulted in suspensions of freedom of the press, freedom of expression, and constitutional guarantees to due process. I'm interested as to whether Galván really believed that this was a viable option for the pacification of the nation, or if it was just a suggestion made in the interest of putting all the options on the table, a la Adlai Stevenson during the Cuban Missile Crisis.
Daniel Hernandez has lots more on the cables at La Plaza. This cable notwithstanding, it seems that most of what we have learned has been official analysis of things we've long been reading in the papers.