The Lapua is going to be around for a while but if ballistics where the only criteria the .338/378 or a wildcat .338 300gr based on the .505 Gibbs ( or reinforced CheTac case) would be the belle of the ball. The Nosler or Dakota give ballistics that exceed normal hunting requirements and allow the use of a standard length action and an extra round in the flush magazine. I loved my .340 Weatherby and lusted for even more velocity but I hated the rifle that chambered it and the need for long barrels to burn the slowest powders. This new offering from Nosler would allow someone to re-barrel or re chamber a standard magnum action with no costly modifications, a shorter bolt throw and an extra cartridge without the need for a 28" barrel a military type magazine and a ghastly muzzle brake.
I personally have no need for more than a .338Win or a 9.3x62 for hunting big game in North America.
But more can be fun. The .338 Norma available as loaded ammo is even more powerful than the 33 Nosler and will fit a standard action with a little coaxing..

.338 Norma case right, .338 Lapua case left. Both based on shortened .416 Rigby case.