I think people are starting to forget the essence of project management: getting the project done on time, on budget, and on scope, regardless of the methodology.
Now about your question on Agile replacing Waterfall, there are many sectors, such as the construction, where the current project management methodology is tested and proven, and I don't think using another methodology will make things better. Agile excels in projects where requirements are fluid (they change all the time), and there are some uncertainties about the shape of the final product (e.g. how would the final product look like). There are many industries that don't have these unknowns, where the requirements are very clear, and where the final product can and will be exactly as the initially planned product. In this case, applying Agile does not makes sense, and may create an unnecessary overhead.