The U.S. Supreme Court has overturned an appeals court ruling that blocked the voter-ID law from being in effect this November. In other words, 2004's Proposition 200 requirement that voters show government IDs at the polls will be in effect for the general election.
This isn't to say the ultimate constitutionality of the requirement has been decided; far from it. All this ruling means is that the U.S. Supreme Court thought the 9th U.S. Circuit Court of Appeals was off base when it blocked the law from being in effect in November.