Apparently that depends on how Justice Kennedy decides. Of the 8 justices on the case (Kagen recused herself) he appears to be the only one whose final stance is unknown. As Lyle Denniston at SCOTUS blog says:
Were Kennedy to vote to uphold the law, despite apparent reservations, the result probably would be a 5-3 win for Arizona. But if he voted to strike down the law, there seemed likely to be only three other votes to go with his, making the vote 4-4 — but Arizona still would win, because such a split vote would summarily affirm a Ninth Circuit Court decision that upheld the state’s worker control law.
However, as he further notes, a split would only apply to that particular case and not more broadly. It would also indicate the probability of any cases that follow it would most likely fail:
Evenly divided results, however, do not set a precedent beyond the individual case, so the result in the future, if all nine Justices took part, might well come out differently: Justice Kagan’s vote could be the swing vote. And other test cases are on the way — including one involving an even broader Arizona anti-immigration law, and a set of alien restrictions adopted by the local government in Hazleton, Pa.
So stay tuned. Worst case for AZ is it gets part of the law affirmed if there’s a split. However it would also mean that the ability for states to address immigration problems would most likely be dead. Supporters have got to hope Kennedy comes down on the side of the right of a state to address the problem that the Federal Government seems unwilling and/or unable to address.