Yaar, the main goal here is to make the newspapers issue an apology, which they have refused to do. Now I don't think that Muslims boycotting those newspapers will make much of a difference since I don't think any Muslim (except may be the ones living in Denmark) read those papers. Boycotting their products would force the affected companies, or may be even their government, to put pressure on the newspapers to issue an apology, so that they stop losing all this revenue.
Again, you cannot force anyone to give an apology when they don't mean it
Boycotting Danish goods is punishing the whole nation of denmark and ordinary Danes who had nothing to do with the whole cartoon thing
Hamza Yusuf opposed this as a collective punishment on all danes