Basically, Scott Walker is saying the judicial system sucks, and he's going to shop for an activist conservative judge that will see it his way. Conservative judges have always been impeccably consistent.
In fact Walker doesn't believe conservative politicians need any judicial oversight, because they are after all, strict constitutionalists. But that's not true of the Democrats. Even though Walker was disappointed when the Republicans lost their challenge claiming the Affordable Care Act was unconstitutional, it's still not really...constitutional in their eyes, so they just won't follow the law. That makes what they're doing oddly, constitutional again.
Walker: "The people of Wisconsin clearly spoke on June 5th. Now, they are ready to move on. Sadly a liberal activist judge in Dane County wants to go backwards and take away the lawmaking responsibilities of the legislature and the governor. We are confident that the state will ultimately prevail in the appeals process."
Here's another explanation, including the judges wording, and rallying teachers at the Capitol's reaction to the decision, from Channel3000: