So "somebody should do something about those Jews" or "I'd be one among many cheering if a bunch of these Jewesses burned alive" - not specific, so it's not inciting?
Either of those, while absolutely vile, should not be restricted speech.
I believe that while the standard currently used by US courts (http://en.wikipedia.org/wiki/Imminent_lawless_action) is not ideal in all circumstances, it is largely functional and has not caused a great deal of harm. In practice, the way it plays out is that it gives hate groups enough rope to hang themselves in the court of public opinion. See: The WBC.
