Tessellation has been touted as one of the major features in newer graphics APIs like DirecX 11, and it is shown as a standalone stage in a modern graphics pipeline.
Compared to the amount of hardware and software attention given to this feature, it doesn't seem to be heavily used in real-time graphics. So this doesn't seem to be a feature that arose out of graphical demand.
Then why did tessellation become such a prominent feature? To cater to the demands of non-realtime rendering? As a side-effect of the increasing shift in GPU architecture as generalized parallel processors in heterogeneous computing? Or is this a forward-thinking feature that will be used in graphics as tessellation-capable GPUs become increasingly common?