This is the hottest rumor that I've read about AMD's upcoming Radeon RX Vega graphics card, so I'll preface it with a this is a hot rumor and could be totally #fakenews so take it with a salt factory in your possession.
The latest rumor names the three different Radeon RX Vega graphics cards: RX Vega Nova, RX Vega Eclipse, and RX Vega Core. Radeon RX Vega Nova will be the GTX 1080 Ti competitor priced at $599, while the RX Vega Eclipse will handle the GTX 1080 at $499. AMD will reportedly price its Radeon RX Vega Core at $399, and will be capable of GTX 1070/1080 performance.
Remember that this is just a rumor, from a site that is providing its own sources from "very reliable sources within AMD's headquarters", which I'm very doubtful of. Anyway, the naming scheme is what I'm looking at - and if Nova, Eclipse and Core are what AMD use for their Radeon RX Vega family - I'm happy with that.
AMD will have up to 7 different Radeon RX Vega graphics cards, as it needs to hit 5 different price points and products from NVIDIA from the GeForce GTX 1070 right up to the GTX 1080 Ti, and even the new TITAN Xp.