62,448,977 in mainland France, divided by 3.7 to 4.1 million Muslims gives a percentage of the population of 6.57%, [thank you, Nigel].
It is a significant minority and rapidly expanding. One estimate puts the Muslim birthrate at three times that of the "indigenous" population. I use the term indigenous with care, as "indigenous" includes Muslims going back many generations.
Nevertheless, whichever way you wish to slice or dice it, it still creates a "problem" like the expanding population of Catholics in Northern Ireland. That is a problem for the Protestants, not initially for the Catholics but then becomes one for them in turn. In France, the strife in the banlieues [thank you, Pedant's Apprentice] is but one manifestation but it's not the only issue in France.
That of laïcité has been around for centuries, at the centre of slaughter and helping spawn philosophers. The matter is not resolved but in the corridors of power, it is the guiding principle. Mixed in with this issue is the taking of citizenship and citizenship rights by so many Muslims and there's a pretty problem:
A parallel process of Muslim enfranchisement is accompanying [the] population surge. Nearly half of the ... Muslims in France are already French citizens. The situation is similar for most of the ... Muslims in Great Britain. Most recently, in 2000, Germany joined the countries where citizenship is granted according to birthplace instead of ancestry. The new German citizenship laws added already a half million voters to the rolls and have opened the road to citizenship to all other Muslims in Germany.
Laïcité is at the centre of Sarkozy's remarks. At pains to redefine the issue as one of oppression and an "affront" to human rights, he understandably wishes to steer the focus away from the religious aspect. Again, whichever way you cut it and I'm not taking sides on the matter, it is a divisive garment, the burqa and the human rights angle muddies the waters and dilutes the opposition to its banning, i.e. leftist thought in France.
It would be interesting to see if the wearing of the cross would follow that; I feel it would not in the forseeable future in what is, after all, a Catholic country and with the political implications with the papacy.
Opinion in France, as Sarkozy well knows, appears divided along political lines:
Cinq ans après la loi de mars 2004 sur le voile à l'école, le problème de l'affichage de signes distinctifs religieux particulièrement voyants et attentatoires à la féminité – burqa ou niqab – suscite à nouveau un vif débat qui transcende largement le clivage droite-gauche.
Le Figaro doesn't seem to be carrying too much on the issue at all. Le Monde carried the Muslim side of the story. An interesting interview in Jakarta from 2004, throws some light on the official Muslim position:
ULIL: Can you estimate how many Muslims in France wear headscarfs?
AF: Statistic indicates that about 80% of Muslim women in France do not wear headscarfs. Hence, only 20% wear headscarfs. Syafiq Hasyim told us that some Muslim figures have said that the matter of headscarf is not an important religious matter. The French government asked the Muslim leaders in France about this and they said that it is not a big problem and that the most important is integration of the Muslim children. Hence, to them, it’s not a fundamental matter.
ULIL: What do you mean by mentioning that secularism benefits the Muslim community?
SH: It is because they are led by the majority law system supporting secularism. If only they accept not laicite or secularism, there will be a chance for the French people to adopt the Catholic system, since their major religion is Catholicism.
In other words, the Muslim spokespeople will make all the right noises against the move but actually, they are not against laïcité per se, as it affords them the best chance of keeping the Catholic Church in check and not reasserting its position within France. The Muslim task of the islamicization of France can then proceed without great hindrance.
From all this, one can conclude that the burqa will be banned but rather than be the next step on the road to the reassertion of France's traditions, it will actually aid in the islamicization of the country.