As to where he he would be sent, as I wrote here, in another press release a few weeks ago (use google translate) , Mexico's Attorney General said the request was made for his 1996 Indictment in San Diego. The case was indicted in 1995, and he was added as a defendant in 1996. That's the case involving the tunnel from Tijuana to Otay Mesa, CA, discovered by Mexico, and the seizure of 7.3 tons of cocaine masked inside cans of chili peppers. One defendant, Enrique Avalos-Barriga, went to trial and is serving life. The others pleaded guilty and were released ages ago.
I uploaded the story from the Government's point of view as contained in its trial brief in the 1996 case here.
Here's the Google translation of today's press release from Mexico.
Mexico, D.F., to July 30, 2015
Bulletin 331/15
In response to a formal request for extradition by the Government of the United States, through diplomatic channels leading, and derived from a process of analysis and diagnosis of such request, on 29 July this year, the Attorney General's Office obtained -from Third District Judge of Federal Criminal Proceedings in the Federal-formal detention order for extradition of Joaquin Guzman Loera District.
During the analysis conducted by the PGR it was verified that the application meets the requirements of the Extradition Treaty between the two countries and with the requirements mandated by the Mexican legislation.
Why would the U.S. seek El Chapo's extradition on a case where the charges are 25 years old, as opposed to more recent cases such as those in Chicago, the Eastern District of New York or the Western District of Texas?
Perhaps the reason it took the U.S. more than a arrest in Feb. 2014 to "update" its ancient extradition request in the San Diego case was so it could include material justifying El Chapo's extradition on cases in some of the other districts as well. (In addition to the districts mentioned above, he's indicted in the Southern District of Florida, New Hampshire, and the Southern District of New York. The Government dismissed the indictment against him in Arizona in 2012.)
It seems to me if the U.S. only sought extradition on the San Diego charges, which is what Mexico said, that's where he would have to be tried, unless the Diplomatic Note contains a request that Mexico waive the rule of specialty. If Mexico agreed to waive the rule,then the U.S. could try Chapo on offenses that occurred after the San Diego offense in other districts.
As to where El Chapo is hiding, while Guatemala, El Salvador and Honduras are possibilities, as is perhaps Venezuela or Cuba, I still think he's back home, somewhere in the mountains of the "Golden Triangle" between Chihuahua, Sinaloa and Durango. His case is more about his talent for corruption and bribery than drug dealing, and if his escape shows anything, it's that his protection is so deep in Mexico he'd be a fool to risk going elsewhere.
The reality is that capturing or extraditing El Chapo or any other "kingpin" will have no effect on the flow of drugs into the U.S. Mexico should be fighting corruption and the U.S. should stop pretending otherwise.