All four of the groups you mention (companies, nations, special interest groups, and consumers) could potentially be stakeholders in cloning and cloning technology, but I believe that private companies and consumers probably have the single biggest interest in this area. Consumers (the end users of cloning technology) could potentially utilize cloning technology to reproduce body parts that could be used for live-saving surgical purposes. The advantages of using a genetically equivalent and compatible cloned organ for a transplant is that the chances of the body rejecting the new organ would be much lower than that of an organ from another person. As a result of this, private technology and healthcare companies have a major stake in the area of cloning in order to service the market of the consumers and generate a profit for themselves. It is not really the end result but the cloning process itself that the companies would be looking to patent in order to insure a return on their research investment.
The legal and moral implications of this are both staggering and complex. Fortunately, cloning science and technology are a long way from being able to effectively and reproducibly clone something as complex as a human being. Even more fortunately, Hollywood has no shortage of creative outlets for cloning technology. A couple of movies on the subject that come to mind are The Island and Star Wars Episode II: Attack of the Clones.