It depends a lot on the development of players like McDavid, MacKinnon, Drouin, etc. but the 2018 team could be - and I'm not afraid to say it - one of the best teams in history. Again, it also depends on the actual McDavid's / MacKinnon's play. But the potential is certainly there. The fact that any of MacKinnon/McDavid/Tavares could end centering a third line says it all.
The talent, and the depth up-front would be getting really nasty if players like Bennet, Monahan, Mantha, Drouin, Barzal, etc., started to reaching their potential.
Don't forget that Nugent-Hopkins is just 21. Then we have players like Skinner, Seguin, Johansen, Duchene, Hall, Huberdeau, or Schwartz, that are still getting better.
I know that a lot may change, but the potential line-up looks crazy. I also personally think that the forward-depth in next 8-10 years is gonna be absolutely ridiculous.