The EU Succession Regulation and matrimonial regimes

To what extent do Civil matrimonial systems interact with the rules of succession? The introduction of the EU Succession Regulation means that this is a real (as opposed to academic) question and we are likely to see contentious cases that pose this difficult question. For an answer (maybe!) please come to the December half day conference: http://www.step.org/special-interest-spotlight-sessions-2015