Fit in a short action, has topnotch factory ammo and seems to be gaining in popularity due to its perceived virtues both real and imagined. Also more manufacturers are adding it to their lineups seemingly daily. As for doing anything better than your 6.5x55.... I doubt it, maybe sound cooler and less European.
Every now and then a perfect storm of manufactures buying in, writers and notable hunters and shooters come together around a cartridge and boost it beyond the recycling wheel of others that perform nearly the same and you get something that truly catches on. The Creedmoor seems to be doing that.
While I wouldn't run out and trade a known proven rifle for it I can understand the appeal. However, if I was in the hunt for a light recoiling .30 cal and under short action rifle that would see use on targets, sub 400lbs critters and the occasional critter going over 400lbs I would probably have to look hard at the Creedmoor. Lets face it lots of the hunting and shooting public do not reload so if a gun has either reasonably priced ammo that performs excellently (like the Creedmoor, .30-30, .270 and .243 Winchester before it) or heaps of cheap surplus bulk ammo it always helps the popularity. As well the cartridge design got a lot of things right that target shooters and rifle looneys are looking for, neck length, shoulder angle, able to seat long high BC bullets for maximum case capacity without needing a longer action and they coupled it with a rifling twist that suits the same bullets.
With all that said I still can't bring myself to want one, at least not for long enough to actually dig my wallet out.