Associated Press reports that the Arizona law may be having the desired effect:
Illegal immigrants plan to leave over Ariz. law

Many day laborers like Diaz say they will leave Arizona because of the law, which also makes it a state crime to be in the U.S. illegally and directs police to question people about their immigration status if there is reason to suspect they are illegal immigrants.

Supporters of the law hope it creates jobs for thousands of Americans.

“We want to drive day labor away,” says Republican Rep. John Kavanagh, one of the law’s sponsors.

An estimated 100,000 illegal immigrants have left Arizona in the past two years as it cracked down on illegal immigration and its economy was especially hard hit by the Great Recession. A Department of Homeland Security report on illegal immigrants estimates Arizona’s illegal immigrant population peaked in 2008 at 560,000, and a year later dipped to 460,000.

The law’s supporters hope the departure of illegal immigrants will help dismantle part of the underground economy here and create jobs for thousands of legal residents in a state with a 9.6 percent unemployment rate.
…
A study of immigrants in Arizona published in 2008 found that non-citizens, mostly in the country illegally, held an estimated 280,000 full-time jobs.

Because of this, Following Passage Of Arizona Law, At Least Seven States Contemplate Anti-Immigrant Legislation. The Wonk Room‘s post shows a chart (below) listing the legal immigration enforcement efforts in Colorado, Georgia, Maryland, Missouri, Nebraska, North Carolina, Ohio, Oklahoma, Texas, and Utah:

STATE	BILL	STATUS
Utah	Require immigrants to carry proof of status, require law enforcement officers to question anyone they believe is in the country illegally, and target employers who hire or transport undocumented immigrants.	Legislation still has to be drafted, but Rep. Stephen Sandstorm (R) claims he “has the support to do it.”
Georgia	Nathan Deal (R), who is running for Governor, wants to propose legislation that mirrors Arizona’s.	Tentatively pending Deal’s election.
Colorado	Today, Colorado gubernatorial candidate Scott McInnis (R) said that if he were governor, he would seek to pass something “very similar” to what Arizona enacted.	Tentatively pending McInnis’ election.
Maryland	State Delegate Pat McDonough (R) “plans to start sending a survey to every candidate for the General Assembly — along with the candidates for governor — asking them whether they agree with Arizona’s approach.”	McDounough’s survey will start being circulated this week as he hopes to “know who is in favor of the Arizona bill and who is not” by this summer.
Ohio	Butler County Sheriff Rick Jones and Ohio Rep. Courtney Combs (R) sent a letter to Gov. Ted Strickland asking him “to employ” his “leadership role” “to assure legislation is passed that will mirror” Arizona’s.	Strickland’s press person says he “hasn’t had an opportunity to review Arizona law” and is concerned it might be unconstitutional.
North Carolina	Local anti-immigrant groups claim that lawmakers have told them that “the chances similar legislation will be filed here is over 95%.”	The same groups also concede that such legislation wouldn’t “get far” in their state.
Texas	Republican state Rep. Debbie Riddle of Tomball says she plans to push for a law similar to Arizona’s.	Riddle says she will introduce the measure in the January legislative session.
Texas	Farmers Branch, a Dallas suburb of 30,000 people, passed an ordinance written by IRLI lawyer Kris Kobach which would prevent landlords from renting houses or apartments to undocumented immigrants.	Last month, a U.S. District judge ruled the ordinance unconstitutional. IRLI is helping Farmers Branch repeal the District judge decision.
Missouri	The state legislature is considering a law, likely written by Kobach, that would make it unlawful for any person to conceal, harbor, transport, or shelter “illegal aliens” and would also make it a crime for undocumented immigrants to transport themselves.	The bill has been referred to the Missouri House International Trade and Immigration Committee.
Oklahoma	Restrict the ability of undocumented immigrants to obtain IDs or public assistance, give police authority to check the status of anyone arrested, and make it a felony to knowingly provide shelter, transportation or employment to the undocumented.	After IRLI filed an amicus brief in the Tenth Circuit Court of Appeals in support of HB 1804, the court refused to reconsider its decision that prohibits Oklahoma from enforcing two of the main parts of HB 1804.
Nebraska	Residents in Fremont Nebraska likely will vote in July on a proposed ordinance to ban the “harboring,” hiring and renting to undocumented immigrants.	Last Friday, the Nebraska Supreme Court upheld a lower court’s ruling that there was no authority to stop an election on the ordinance following a petition filed by Kobach.