AMD Radeon Technical Marketing guy Robert Hallock revealed on Twitter that the new Polaris SKUs will be shipping around mid-2016. Whether that's actual availability or a paperlaunch is unknown of course.
VideoCardz also noticed some odd tweets from other members of AMD's marketing team. Take it with a grain of salt (or spice), but they seem to be giving hints about the transistor count of Polaris.
Of course assuming this is anyhow related to transistor count is in my opinion an exaggeration. By reading in-between the lines we could get an impression that the Capsaicin (chilli peppers active component) chemical notation mentioned in the tweet could somehow refer to 8.6 billion transistors.
@GFXChipTweeter As I've told you 16 million times, nothing less than the 8-methyl-N-vanillyl-6-nonenamide-infused Carolina Reaper will do...