Virtualization of network/service functions means time-sharing network/service (and affiliated) resources in a hyper-speed manner. The concept of time sharing was popularized in the 1970s with mainframe computing. The same concept has recently resurfaced under the guise of cloud computing and virtualized computing. Although cloud computing was originally used in IT for server virtualization, the ICT industry is taking a new look at virtualization. This paradigm shift is shaking up the computing, storage, networking, and service industries. The hope is that virtualizing and automating configuration and service management/orchestration will save both capes and opex for network transformation. A complimentary trend is the separation (over an open interface) of control and transmission. This is commonly referred to as software-defined networking (SDN). This paper reviews trends in network/service functions, efforts to standardize these functions, and required management and orchestration.