A change in how Mexican presidents conduct business: the executives no longer have to ask for permission to leave the country, they simply need to inform the Senate unless they are going to be abroad for a long stretch. This should eliminate embarrassing moments of lame duck-ness, such as when a spiteful legislature denied Vicente Fox approval to go to a forum in Asia toward the end of his term.
This follows a recent in change in the informe (Mexico's state of the union address), which no longer has to be oral, merely a written statement. This is a clear upgrade. Putting to one side the plight of the poor presidents who had to stand speaking about endless governing minutiae for hours at a time, the relevance of the speech in recent years was based less on the speech itself than on the protests surrounding the event. Basically, the informe made the president a giant target in a battle of asymmetrical rhetorical warfare.