The Supreme Court in a 5/3 vote (Kagan abstained because she worked on the case) decided that the Arizona law that penalizes employers for hiring illegal aliens does not interfere with federal law.
Of course the three dissenting judges were Breyer, Sotomayer and Ginsberg.
This isn't the big battle, though, so don't get your hopes up. The Bush administration had already agreed that this law delineated an acceptable use of the E-Verify system, although that didn't prevent the Obama Justice Department from taking the opposite (losing) tack.
SB1070 is still in the works, so keep your eye on the ball.