This is not a new problem and was even simmering when I was living there (12 years ago). In fact, La Haine was released just after I came home. I have previously mentioned my fears about France's propensity towards authoritarinism. (@#$@#% can't find the post now, so no link.)
If this continues and we see a retread of the violence we saw in "the zone" (as they call it) like we did last year, I fear the backlash will be severe and only serve to escalate the situation.
France has created this problem by isolating the immigrants and granting them extensive bread and circuses. They do not have, or need, jobs. They merely live off the dole (like many Frenchmen) which is bad enough but they are shunned by mainstream society and what few jobs there are, do not go to brown people. If you ever think Americans are bigots, spend sometime in Europe. We're pikers compared to them. There is no easy solution. If they try to integrate them into mainstream French society, they'll be met with resistance from both sides. The Magrev will shout about the loss of Muslim identity and the Gaulists will decry the loss of French identity. Either way, it's going to be a long and painful process to solve the problem.