The Irregularities of the Mexico 2012 July 1st General Elections

The Mexico July 1st 2012 elections had a turnout of 63.1%, which is slightly more than 2006 (59%) and about the same as in 2000. After the first count Enrique Peña Nieto (PRI-party) had 18,727,398 votes (39.10%) and won the elections. Andrés Manuel López Obrador (PRD-party) had 3,192,281 (6.67%) votes less: 15,535,117 (32.43%). López Obrador did not recognize Peña Nieto's victory, claiming there had been widespread irregularities. López accused the PRI of spending more than their allotted electoral budget, biased media coverage (Televisa) and vote buying. So how serious are these allegations and what's López Obrador's chance in this rearguard action about the presidency?