The gang at EliteBastards have taken some information posted by the infamous Uttar in a Beyond3D thread and consolidated the data into a much more easily digestible form for your viewing pleasure. Here, an interesting slide from an older NVIDIA presentation was found which discusses the creation of "Mutli-Function Interpolators" with a reference to being implemented in an unannounced future GPU. In short, this is a method in which a shader can be created using less transistors resulting in lower density, smaller die size, reduced power consumption, and potentially higher frequencies. For more information, be sure to investigate the presentation which is linked at the bottom of the page.
"In the 3D rendering pipeline, there is rarely any need to fully utilize both the attribute interpolation units and functional units for handling special functions at the same time, meaning that at any one time during 3D rendering, one or the other of these functional units is left either underutilized or unused, resulting in what is basically a waste of both power and die space. Thus, NVIDIA's plans circa G80 seems to be to combine these two functional units into one single, shared functional unit which can process both the necessary interpolation techniques as well as handling the processing of higher order functions. This has the obvious benefit of reducing both die size and transistor consumption, without sacrificing much in the way of performance. Indeed, it has been pointed out that in NVIDIA's current architectures, the interpolation units are a major bottleneck where more attributes can require interpolating for vertices than the interpolation unit can handle. It seems sensible to assume that the move to 'multi-function interpolators' will also see NVIDIA working to either ease this bottleneck or remove it entirely."