The big deal about this card can be summed up thusly: "AMD is planning on heavily promoting the VR aspects of the RX 480, as it brings the necessary performance down from a 250W, $300+ card to a 150W, $200 card."
So the card is more accessible from a financial standpoint and the 100W decrease in power draw means that it both reduces the overall cost of a new build in addition to its own lower cost by requiring a less beefy power supply and makes it a viable option in a greater array of existing desktops without needing to also upgrade the current power supply.
If AMD released decent Linux drivers I might consider it over an Nvidia card, but as things stand now they're useless in a Linux box, and useless in a Windows box (but that's just because it's windows)
So the card is more accessible from a financial standpoint and the 100W decrease in power draw means that it both reduces the overall cost of a new build in addition to its own lower cost by requiring a less beefy power supply and makes it a viable option in a greater array of existing desktops without needing to also upgrade the current power supply.