With the advent of technologies such as gigabit ethernet and DWDM, combined with large investments in fibre capacity made over the last few years by service providers, it is tempting to argue that quality of service is no longer relevant. This talk will examine the issue of whether QoS mechanisms are in fact needed. We begin by considering QoS from the perspective of application needs, and then examine the general mechanisms that are available to provide QoS that meets those needs. Using both empirical data from the Internet and some simple models of network behavior, several arguments against the simple overprovisioning approach will be presented. We consider the factors that affect the decision of whether to deploy QoS mechanisms or to add capacity. Finally, the state of QoS deployment in a range of different classes of network will be discussed.