title: AnyObject? does not have a member named 'objectAtIndex'
body: <p>Got a error on (Xcode6 BETA 6) if a try to get an object of string:</p>
  
  <pre><code>let jsonString : String = "[{\"name\":[\"Fred\",\"John\"],\"age\":21},{\"name\":\"Bob\",\"age\":35}]"
  
  let myData:NSData? = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: true)
  
  var jsonResult:NSArray = NSJSONSerialization.JSONObjectWithData(myData!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSArray
  
  println(jsonResult.objectAtIndex(0).objectForKey("name").objectAtIndex(0))
  </code></pre>
  
  <p>print never get called, cause the error. Anyone a idea?</p>