No, what's down are apprehensions. At best, we have a slower rate of growth of the Illegal Alien population in the United States. By any estimate, there are now a couple of million more Ilegals than there were in January of 2001.
There are other factors that might account for the reduction in apprehensions. Since over 90% of apprehensions occur within three days of crossing the border, a reduction could be the result of fewer back and forth border crossings by Illegals since 9/11.
Also, the sluggish economy has reduced demand for Illegals.
There's plenty of spin coming from the Feds on Illegals, but not much in the way of actual results.
No surprise, really, since the plan is Amnesty by "guest worker" anyway.