I feel positive of the outcome. During the campaign I was afraid of a PRI landslide.
The most important thing is that PRI did not get a majority in either chamber of Congress. They'll have to negotiate. This pushes back the spectrum of "an imperial presidency", much of the like of old priistas. It makes it difficult to return to the "old regime", even if there is the temptation in the incoming government.
I think Peña Nieto will do better than Calderón in both the economy and security (as I posted before, this is not very difficult). I also think that our traditional (1930s-1990s) foreign policy will help put Mexico back in the place in the world it had before the advent of the "drug war". Peña Nieto will be partner with the US, but will not lick the boots of American interests the way Calderón did.
My main preoccupation is about the authoritarian knack of the PRI. There will be loads of propaganda, and lots of concessions to the big TV duopoly. But I think Mexican society will not tolerate it.
The key to the future, IMHO, depends on what the left does with the result. If they decide to follow Lopez Obrador's tantrums, and radicalize, they'll leave the ground for a very pro-business PRI-PAN entente, when this country needs more economic equality. If the left behaves "institutionally" (as we say), it will clearly position itself as the main opposition to Peña Nieto and a reliable option for future national governments. The attitude of the moderate leftists is important. So far, the (left wing) governor of Oaxaca has declared he will collaborate with president Peña. The mayor elect of Mexico City declared that wil also collaborate with him "pending the definitive result of the election". If they manage to isolate AMLO and his cronies, they'll do both Mexico and Mexico's left a big favor. Not an easy task, though.
Finally, I am very happy Calderón had his comeuppance.