Originally Posted by
Ancien Maestro
The engineers should continue to evolve the model to modern specifications and fuel efficiency, but I guess eventually a model change due to market differentiate.
Everything remaining the same, and 45 years later, eventually the 747 imho will become obsolete unless updated to continually meet market requirements and rigors.
They did, it's called the 777x.

The 747-8i was an attempt to evolve the design to modern specifications but there's only so much you can do with 4 engines. The 777x will have offer a plane that carries almost as many passengers (it has a longer wingspan and fuselage than the 747) but for significantly less fuel for seat mile.