Classical nonlinear planning has been studied in the abstract since the early 1970’s. More recently, interest has grown in applying these techniques to real problems, or at the least to simplified versions of real problems. In this paper, we explore some of the implications and results of those applications, with an eye to addressing the question of where the main problems lie. What successes have been achieved? What remains to be done? In particular, what fundamental representational or algorithmic issues, if any, need to be addressed before classical planning becomes a useful tool for large, complex, real-world problems?