The cartoons were originally commisioned to test the boundaries of free speech in Denmark. An ethnically Danish author who was writing a pro-Muslim children's book on Islam, couldn't find anyone to illustrate it for fear of violence and persecution from the Muslims in Denmark. He questioned whether political correctness in regards to Muslims was hindering free speech in the country. The newspaper drawings were meant as a test--granted, a rather childish one. The smarter option would have been just sketch with no political implications, but even then it would still be offensive according to Islam: ALL images of Mohommed are offensive in that religion!
While the drawings were pretty incinderary, a more "PC" representation would probably have caused just as much of an [violent] outcry. Many Muslims themselves didn't help matters with threats of death and violence. They protest (in part) their religion being represented as one of violence and terror, so to combat this stereotype they engage in....violence and terror? Yeah, that's smart. I can understand why they were angry, but I'd have to side with the Danes and other Europeans of this one: Denmark is a sovereign nation with a long history of liberalism and free speech. Danish newspapers publish whatever they damn well please, even if it is rather silly and offensive. It seems that for many people who side with the Europeans the issue is that Muslims are trying to force their blasphemy laws onto a secular society.
As for the double standard, there is a report that the same Danish paper refused to publish images which Christians would find offensive, but western Europe (and America) as a whole aren't shy about mocking Christianity...or politicians, or religions figures, or anything else, for that matter. And it's interesting that no one seems to have noticed that Muslim newspapers were publishing the most awful propaganda against Jews and others long before the Jyllands-Posten decided to turn agent provacateur. Not that this justifies the assinine move taken by Jyllands-Posten, but if we're gonna play the "hypocrisy card" it should be played equally.