From BBC News:
The Mexican security forces have arrested 11 alleged members of the country's most powerful drug gang, the Sinaloa cartel....
During the raid, elite troops killed the regional leader of the gang, Luis Alberto Cabrera Sarabia....
Mr Cabrera Sarabia is accused of having controlled much of the drug trafficking in the two northern states.
Gen Trevilla Trejo said Mr Cabrera Sarabia had been personally chosen to head the Sinaloa cartel's operations in the region by its leader Joaquin "Shorty" Guzman.
He was appointed only last month, after the arrest of the previous regional leader, Luis Alberto Cabrera Sarabia's brother, Felipe.
If the article is right, this suggests that the Sinaloa cartel has developed a succession mechanism that readily appoints replacements after mid-level leaders are killed. My research indicates that this strike will have zero effect on cross-border trafficking, but will likely be followed by an increase in violence over the next few months.
Pretty much everyone who has looked at this topic agrees that reforming Mexico's government is crucial for future stability. Why hasn't that happened then? See this piece from The Economist. (I especially loved the correction at the end.)
Update: I've added a Working Papers page, where you can find the latest draft of my research on Mexican DTO's.