From the letter to Holder:

We have very real indications from several sources that some of the gun trafficking "higher-ups" that the ATF sought to identify were already known to other agencies and may even have been paid as informants. The Acting Director said that ATF was kept in the dark about certain activities of other agencies, including DEA and FBI. Mr.Melson said that he learned from ATF agents in the field that information obtained by these agencies could have had a material impact on the Fast and Furious investigation as far back as late 2009 or early 2010. After learning about the possible role of DEA and FBI, he testified that he reported this information in April 2011 to the Acting Inspector General and directly to then-Acting Deputy Attorney General James Cole on June 16, 2011.

And, just to add to the mess,
Virginia O’Brien, Special Agent in Charge at the Bureau of Alcohol, Tobacco, Firearms and Explosives Tampa Field Division, ran a gun-running investigation that was walking guns to Honduras using the techniques and tactics identical to Fast and Furious, it was reported to these correspondents this evening via private correspondence from a proven credible source.
...
SAC O’Brien was previously the Special Agent in Charge of the Phoenix Field Division, was later promoted to the Deputy Assistant Director of ATF, but then stepped down to the position in Tampa. Whether the allegations of our source refer to the ongoing Operation Castaway remains at this hour unclear, but our source is certain that O'Brien has allowed the "walking" of straw-purchased firearms to Honduras using the same failed strategy as the Phoenix Field Division's Operation Fast and Furious. That Operation Castaway involved arms smuggling to Honduras is also certain.

"This is confirmed as accurate," the correspondence continued. "There are emails in existence where O’Brien has advised those involved that Tampa does not have to report their walked guns because Tampa FD is not a part of Southwest Border or Project Gunrunner."

"From a first person source she is sh*tting herself trying to cover it up," the report stated.
Oh, this is just friggin' wonderful, isn't it? Honduras? Why?
First, and this is important to understand: the Tampa operation proves beyond a shadow of a doubt that "Project Gunwalker" was a national strategy, not a Phoenix aberration. The "major media" has been slow to understand this. They have ignored the fact that the Houston Field Division had to have played a supervisory role in known straw buying incidents in Dallas and Columbus NM as they are in their area of operations, not Phoenix's. Original reporting on this subject from Texas has been pitiful.

Second, Honduras is where the action is.
...
Honduran officials report that Mexican drug traffickers are expanding their activities in the country and forming links with local bosses in four different provinces, fuelling concerns that organized crime is overwhelming the region.

According to Prensa Latina, Security Minister Oscar Alvarez said that the Sinaloa Cartel and the Zetas have been detected in Ocotepeque, Copan, Colon and Atlantida. The four northern states form much of the Atlantic coastline in Honduras, as well as a large chunk of the border with Guatemala. The Mexicans, Alvarez said, move freely throughout these regions, but rather than seeking to take over areas, the foreign gangs are working through already existing networks of local bosses to increase their presence and expand their operations.

Oh, and about the Mexican Gun Lie:
As InSight has reported, Guatemala's military stockpiles have been filtered illegally to the Zetas criminal gang. On top of this, according to a 2008 U.S. diplomatic cable first obtained by WikiLeaks and recently released by McClatchy, the Honduran military has “lost” several U.S.-supplied military weapons in recent years.

The cable, avaliable below, cites a Defense Intelligence Agency report entitled “Honduras: Military Weapons Fuel Black Arms Market,” which noted that the serial numbers on light anti-tank weapons recovered in Ciudad Juarez, Mexico and San Andres Island, Colombia, matched the numbers on guns that had previously been sold to Honduras. In addition to the guns, U.S. authorities seized a number of M433 grenades from criminal groups in Mexico, which were also traced back to the Honduran army.

Such revelations, when paired with recent allegations of high-level government links to drug trafficking in Honduras, present a dim forecast for anti-arms trafficking efforts in Central America. They also add fuel to an already heated debate over the cartels' main source of arms. While testifying to the U.S. Senate on March 30, General Douglas Fraser, the head of the U.S. Southern Command, implied that corrupt military officers in Central America bear most of the responsibility for arming Mexican drug traffickers.

"Over 50 percent of the military-type weapons that are flowing throughout the region have a large source between Central American stockpiles, if you will, left over from wars and conflicts in the past," said Fraser.
And now we know that a lot of the AR's and AK clones that actually did come from the US were aided in getting to Mexico by ATF.