The attack on Charlie Hebdo is an absolute travesty. My heart goes out to the cartoonists, columnists, editors, policemen, and other innocent victims.
Absolute freedom of speech is a human right. From Paris to Riyadh, anyone is free to draw and publish cartoons of the Prophet and any aspect of Islam that they disagree with. Not only should critical discourse be tolerated, it should be welcomed, for it leads to introspection and self-betterment.
I believe that a majority of muslims living in the west would agree with me. Many might have been offended by the cartoons, but one does not choose to live in a free society if they can't handle opposing points of view. Unfortunately, this doesn't come through in the statements of muslim "representativates" on TV who are quick to condone acts of violence but seem hesitant to categorically dismiss the ideological basis for the violence (i.e. the cartoons shouldn't have been published). This is probably because their jobs depend on carefully towing a line between religious ideology and political correctness.
Again, I don't think the cartoons are an issue for msot muslims in the west. I suspect the motivation behind the gruesome attacks in Paris might have been to make them a bigger issue, with the ultimate objective of sowing internal discord and recruiting more troublemakers. Perhaps the perpetrators play upon the expectation that the public discourse will inevitably drift to "why are muslims violent and dangerous and opposed to cartoons of the prophet?". Young mulsims will inevitably face this discourse in schools, in the press, on TV, and may eventually start to believe it and feel isolated. This might mold them into targets for further brainwashing and recruitment.
I think that we, as a society, need to get a lot better at understanding these criminal motivations. Forcefully reacting to these acts of violence is simply not enough. If we fail to control the discourse, I'm afraid such violence is likely to continue.