The Seventh Circuit Court of Appeals has reversed the district court and upheld Act 10—otherwise known as Scott Walker's collective bargaining bill—in its entirety. The opinion is available here. A state court action seeking to invalidate the law on various bases remains pending.
ORIGINAL POST (3/30/2012):
A federal district court judge in the Western District of Wisconsin has struck down portions of Scott Walker's bill rolling back collective bargaining rights for public employees. The opinion is here.