We know Fate Reforged is the crux of the "Time Travel" aspect of Khans of Tarkir block (how went your prerelease, by the way?). Anyway, this is the set where the time travel begins as we look at Tarkir in the past.
And also the future.
If you look closely, you can see that this Crux of Fate was marked with not just the normal watermark, but also the Dragons of Tarkir watermark, a little easter egg throwing forward to the final set.
It's another sign of how deep the WOTC team hides stuff like this. We see something new every year, or it seems, every set. Really makes you wonder what all we're missing...