Linux servers deployment growth slowing, are we at a crossroads?

IDC reports that Linux deployment growth has slowed dramatically to the point of reaching negative growth, making it loose market share compared to windows. The interpretation of these numbers are that the easiest migrations from Unix have now been done, and that we are entering a new stage of Linux' presence in the enterprise. Microsoft's vision is that Linux' market share will now stagnate because "Linux is primarily deployed in two workloads—high-performance computing and as Web servers". Another interpretation is that as easier Unix migrations are done, Linux vendors will have to take on Microsoft directly and compete on big ERP, CRM and databases deployments.