It looks like AMD was using its next generation GPU at the Game Developers Conference, without much fan fare. PC Perspective was there, with Ryan Shrout reporting that AMD was using its next-gen video card to power an Oculus Rift demo.
Shrout met with AMD shortly after, where they told him that the not-so-great looking system was powered by the "upcoming flagship Radeon R9 video card" but nothing else was said. Shrout asked if he could take the side panel off, or look at the driver, or GPU-Z, but he was shut down for every single option.
Then we have KitGuru reporting that AMD will launch its new Radeon 300 series, including the Radeon R9 390X at Computex in Taipei, Taiwan in June. We know that AMD has confirmed new GPUs for Q2 2015, so we should expect an announcement in the next 4-6 weeks, with a full retail launch in June? Surely AMD wouldn't wait until June to launch its new GPU when NVIDIA has just unveiled its GeForce GTX Titan X.