I have a stock 290, and (if the 480 delivers and gives me the same or better performance on a lower power budget) ill be getting one.
AMD are targeting a market where nvidia seem to neglect at first, a lot of people want in on VR but a £400+ card is out of reach or impractical. A £200 card that can play most VR games would A) be a better fit and B) sell better as more people can afford this.
Now a lot of people argue that if you spend £600-700 on VR equipment you will fork out another £400-500 on an amazing GPU, i don't think thats the case. Also remember there will be a lot more VR headsets out in a few months that will drive the prices of these down a fair bit (Vive and Rift are only expensive as the market only has 2 silly priced options)
Also iv seen many people on here say "go buy a 970", sure but they are only cheap as they are the last of stock that needs to be shifted .... that and the limited VRAM. The 980 (performance that looks to be on par with the 480 information we have) is still at £300 :/