I don't know where to begin or end. I will say that the two Parisian residents (one past, one current) that I've spoken to have both emphasised that they've seen clear and unashamed manifestations of racial prejudice by gendarmes in the city: strip searching Arabic men publicly in a train station, and the kind of aggressive 'routine check' of guys of African descent that still probably happens in the UK, but maybe not in quite such a brazenly public way.
An interesting development today is that bloggers have been accused of inciting some of the violence.
Weirdly, I bought La Haine on DVD about a week before the riots started. When it hit the cinemas in the mid 90s it made such a stir that the French PM convened his cabinet for a special screening of the film, an action that implied (i) that they had no idea what life was like in the suburban slums of their big cities, and (ii) that they were subsequently going to do something about it.
(ii) obviously hasn't happened. You just have to hope that it will now. If this is France's Brixton '81 (as in the pic above), and greater racial integration, regeneration projects, and crucially a massive attempt at reform within the police force is to follow, then there's some reason for hope. It is just hope though, nothing more.