Gaga will never again have the cultural impact of her debut. A volcano can only erupt for so long. She needs to either get away from dance music or make pretty much the best dance album ever.
Just to continue your analogy there, a volcano often has a lifespan of many millions of years and can erupt many many times during its life.
I think she could easily make another serious impact on pop culture, she just needs to play everything right. If she meant what she said about it being less serious then that's already a massive leap in the right direction for a more commercial appeal again. I just hope there's still some substance in the material, I have no doubt there will though with Gaga.
I think she's already made an error by announcing the album title when the release date is next Spring.
Also, didn't she say that she was announcing the album title in September, is there still going to be an announcement in September or is that void now?
I am very excited to see everything unfold though, in typical Gaga fashion.