The .243 isnt going anywhere. It will take the 6.8 too long to catch up to the .243 in popularity. Another thing is it will probably go through a name change like the .280 remington did. It started out as 7mm-06 then went to 7mm Remington Express then finally the .280 Remington over several years. The 6.8 Will probably do the same if you give it time.