Interesting that the new cards are said to be R9 470 and R9 480. No "X" suffix. That indicates to me that we may be seeing only cut-down SKUs at first, much like we did with Tonga. The rumors so far have Polaris 10 with 2560 shaders on-die, but only 2304 enabled on the card (four CUs disabled). Polaris 11 is often speculated to have 1024 shaders, but it wouldn't surprise me at all if it actually had 1152 or 1280 on-die, and the first retail cards disabled two to four CUs. The best (fully-enabled) bins could be reserved for higher margin mobile products, like this year's 15" Retina MacBook Pro.
Later this year, we could see the R9 470X and R9 480X, with fully enabled GPUs once yields improve. Maybe GDDR5X as well. Presumably, the Tahiti-sized Vega GPU will be called the R9 490(X) when that comes to market near the end of 2016 or beginning of 2017, and the big (Hawaii-sized?) Vega will get a special name, either some variation of Fury or something new.
As for pricing, both the names and chip sizes may offer some clue. The current R7 370 card debuted at $149, and the R9 380 at $199. Back in 2012, the 7750 (cut-down 123mm^2 Cape Verde) started at $109, while the 7850 (cut-down 212mm^2 Pitcairn) began at $249. Given these precedents, I wouldn't be surprised to see the R9 370 at $149 and the R9 380 at $249.