Mexico US undocumented immigration is dropping

Here's an interesting trend pulled out from the Department of Homeland Security's website.

The number of Mexican undocumented immigrants residing in the US has stopped increasing and started dropping in 2010. Meanwhile, the number of naturalized is growing tremendously.

Naturalizations could not come as part of immigration (those would be legal residents rather than naturalized), up to 2009, there doesn't seem to be an increase in immigration from Mexico due to the drug war.

Given that today the NYTimes reported Mexicans are flooding into the United States due to the war (link). I wonder if that is a new trend on 2010, since the from previous years immigration to the US from the drug war seems to be overshadowed by migrants moving back to Mexico due to lack of jobs.