Valantar :
Also, I disagree that there isn't room for another SKU within $60 - after all, third party coolers and other stuff already muddles the pricing quite heavily. The current R7 360 sits around $100, while the R7 370 starts from around $140, and the R9 380 around $180-200. In other words, their current lineup has room for three GPUs within less than $100.
Anything slower than the R7-370 will be rendered obsolete by next-gen APUs and IGPs, there is an increasingly limited future below the 470. Having that many tightly priced and similar products is horrible for gross margin since it artificially segments the market into multiple unnecessary bins and multiplies development effort by that much. Getting rid of some of that fragmentation would reduce AMD's R&D costs and the bigger performance gap between product lines will make it easier for people take the relatively small price bump for the large performance increase.
Yes, the RX-480 may have defects but keep in mind that only the RX-480 has been announced. Based on the old rumor that the 480 may have 2560 shaders, the RX-480 may already be a cut-down version with four CUs disabled for yield flexibility. Same goes with the 470 which has rumors of 1280 and 1024 shaders.
Where product naming is concerned, the lineup between 470 and 480 appears to be full.