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.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.
At this point all it has to do is beat the 970 and the competitive pricing.