Barack Obama wants Congress to allocate $500 million in order to send up to 1200 National Guard troops to the border. Per an unnamed administration official (link):

"[The troops will] provide intelligence; surveillance and reconnaissance support; intelligence analysis; immediate support to counternarcotics enforcement; and training capacity until Customs and Border Patrol can recruit and train additional officers and agents to serve on the border... [the funding will be used to] enhance technology at the border, share information and support with state, local, and tribal law enforcement, and increase DoJ and DHS presence and law enforcement activities at the border, to include increased agents, investigators, and prosecutors, as part of a multi-layered effort to target illicit networks trafficking in people, drugs, illegal weapons, and money."

It's very important to bear the context in mind. Securing the border is vitally important, and this is great news from that standpoint. However, it's also important not to be snookered: the Obama administration might declare the border secure after a few months and then use that to push comprehensive immigration reform, aka amnesty. And, since most political leaders that discuss immigration matters from the "tough" standpoint harp only on securing the border, this might be seen as Obama playing a political game in order to "give them what they want", in order to get what he wants.

And, it's important to bear in mind that this follows Obama welcoming Mexico's president to the White House with open arms, with the Democrats in Congress going as far as giving Calderon a standing ovation for opposing a law supported by 60% to 70% of Americans.

And, it's important to keep recent history in mind. Recall that just over four years ago, Karl Rove supported putting the National Guard on the border, just as then-Arizona governor Janet Napolitano had requested. That "Operation Jump Start" made for a wonderful photo op with George W Bush, but the goal was clear: look like they were doing something in order to get amnesty.

Then as now this is a good move, although it's very important to make sure it's not a prelude to something else.

UPDATE: In case all of the above wasn't clear, the Mexican government has now weighed in (portal.sre.gob.mx/usa/
index.php?option=news&task=viewarticle&sid=297):

Regarding the Administration’s decision to send 1,200 National Guard servicemen to the US Southern border, the Government of Mexico trusts that this decision will help to channel additional US resources to enhance efforts to prevent the illegal flows of weapons and bulk cash into Mexico, which provide organized crime with its firepower and its ability to corrupt.

Additionally, the Government of Mexico expects that National Guard personnel will strengthen US operations in the fight against transnational organized crime that operates on both sides of our common border and that it will not, in accordance to its legal obligations, conduct activities directly linked to the enforcement of immigration laws.

It'd be interesting to know exactly what "legal obligations" they're referring to; obviously they have no right to tell us how or where we do immigration enforcement inside the U.S. That said, there's a good chance that Obama has already agreed to the Mexico's demands and this current move is one result of an agreement made on Calderon's recent visit.

5/27/10 UPDATE: Now the State Department is confirming that they and Calderon are on the same page (link):

President Barack Obama on Tuesday authorized the deployment of up to 1,200 additional troops to border areas but State Department spokesman Philip Crowley told reporters, "It's not about immigration."

He said the move was "fully consistent with our efforts to do our part to stem, you know, violence, to interdict the flow of dangerous people and dangerous goods -- drugs, guns, people."

..."We have explained the president's announcement to the government of Mexico, and they fully understand the rationale behind it," Crowley said.

Crowley was formerly with the Center for American Progress.

And, from this:

President Barack Obama's Democratic allies in the Senate have repelled a move by presidential rival John McCain to send an additional 6,000 National Guard troops to the U.S-Mexico border... The Arizona Republican says the security situation along the order has deteriorated so badly that 3,000 guard troops are needed just to help protect his state. But McCain failed to muster the required 60 votes for his plan as the Senate continued debate on an a war funding bill.