Earlier this week, Overwatch Game Director Jeff Kaplan revealed that “golden gun” cosmetic rewards will be handed out to qualifying players of the not-quite-there-yet Competitive Mode. Today, previews of those images, taken from the Korean public test realm and posted on a Korean forum, and they are very golden indeed.
As is the way with anything that appears on the PTR, these images are not carved in stone, and may not end up in the full game in their current state, or at all. But they are as described—golden and guns—and the inclusion on a big ol' golden hammer certainly indicates that, if nothing else, this is what Kaplan was talking about.
There are 26 images in total (MasterOverwatch is probably the easiest place to see them all) and I've reached out to Blizzard to confirm that they are in fact legit, but I'll quite surprised if they are not. In the meantime, you like?