Yes, in a basic sense your 'hypernurbs' are similar to subdivision surfaces - subD's are mostly smoothing polygons. However, they can usually be considered their own geometry type - for example, in maya, they obey their own rules, which include differences in how they must be textured. Umm, near as I know, you can't export a straight subD model to a game platform (however, I've never really exported anything to a game engine, so...).

A couple quick things about normal NURBS....
FIrst, I'm pretty sure that all objects in maya are rendered as polygons - that is, during the render process, and nurb object is converted to be a polygon. This has no actual effect on the actual geometry, and in many cases will have no major effect whatsoever. Just something to keep in mind.
Second - although you can do pretty much the exact same type of work with nurbs that you previously described, nurbs are considered their own seperate entity, and have some rather idiosyncratic tools. Playing around with them is probably the best way to get a feel for these objects.