Most mobile applications are content based. Personally, I would like to see less content specific applications and more applications that solve existing problems (i.e. cross-platform, carrier) with mobile devices. Having researched the space, I understand why most developers choose to go with a content based application. Application development is not easy to begin with and the phone technology will change. Now it appears that a king of content, Amazon (Disclosure: The wife is an employee) is blocking mobile applications from using their content, or rather more actively enforcing its own existing rules. Amazon is defending its turf. Expect no less from any content provider.
Expect to see more of this strategy from large content owners. Seriously think about any type of content dependencies before you build that next, great mobile application. Check TechCrunch: Amazon Killing Mobile Apps That Use Its Data for more details.