Really interesting debate. The 'Y-Word' will likely follow the same path as the 'N-Word', it will be adopted by a group as a defence mechanism or an identity to shock as required. Search for the Richard Pryor live show on i-player for evidence.
In a much more minor way I often introduce myself as a Pommie or Soutie when I am in South Africa, I get it in before I get any stick from the Dutchmen (excuse the racist term)
My personal standpoint is that I wouldn't call a Jew or a Spurs fan a Yid, what they choose to call themselves - I couldn't give a ****.