The article is gated, but El Universal has a poll showing a 56% approval rating for Peña Nieto after 3 months from Buendía y Laredo (Full description and details of the poll there). Given the number of reforms he’s pushed through, I’m actually surprised it’s not a bit higher. As the pollsters note, the PEMEX explosion hurt the government’s image.
By way of comparison, that number is above Obama’s current rating (unsurprisingly), though lower than the 67% approval rating that Marcelo Ebrard had at the end of his term as Mexico City’s mayor. The same Buendía y Laredo poll, perhaps most surprisingly, gave Calderón a 64% overall approval rating at the end of his term. The rejection ratings for Peña Nieto and Calderón are rather close though, 29% to 25% respectively.