I agree, but Mid-Range is determined by Price. Nothing else. If the Nano comes out priced to compete with the 980, it's not a Mid-Range card. The 960 is a Mid-Range card, and it is so because of its price, and nothing else. If it costed the same as a 980, it would be a High-End card. It would be a terrible High-End card, but the words 'High-End' would be use to describe it. So really, the only thing that would make or break the Nano as a Mid-Range card is the Price. It would have to be priced to compete with the 960, which the 380 already does. So I highly doubt we'll see the nano in the same price bracket. In fact, I would venture a guess that the Nano would be priced to compete with the 970 or 980, based on AMDs recent 390 launch.
While your assumptions aren't with out merit I don't think they would try to shoe-horn the Nano into a segment, I bet it will be placed along side the 380-390 series.
At this point all it has to do is beat the 970 and the competitive pricing.