Definitely interesting, and an improvement if they're getting a little more performance out of a little less power consumption.
Still, the (admittedly far more power hungry) RX 570 is the target this really has to beat. If it only manages a tie, but costs more, it still is a bit of a tough sell. I'm not quite sure if it manages a tie, though. Maybe close?
It'll be interesting to see when official benchmarks come out - and probably worthwhile to compare it to both the 4GB and 8GB versions of the RX570.