In the ~3 years I have worked at a gun store, the 6.5 Creedmoor has been the best selling cartridge every year. I could count the number of .30-06 I sell each year on one hand.
But here's a little about the community where I live: we are an aging population that is quite flat and mainly hunts whitetail, mule deer, and pronghorn. It is not uncommon to have shots at game over 350 yards. The Creedmoor is perfect for our area. Many retired guys have traded in their .300 Win Mag's and .30-06's and gone with the lighter recoiling cartridge. I also sell many of them to younger hunters who aren't quite ready for a heavy recoiling cartridge.
As an example of how popular it is up here, I sold 4 cases of Hornady Precision Hunter 143 ELD-X rounds in a day and a half during dear season. Four cases of Premium rounds, not el topo cheapo round.