I wish that I had your optimism, Ben, but they don't look like potential contenders to me and it doesn't really feel like an exciting time to follow the team, not as long as McLellan is coach. I can't see them going anywhere with him behind the bench, and Blake has confirmed that he'll be returning next season. Also, knowing that they (or, specifically, McLellan) can't beat a team that they're almost guaranteed to face in the 1st or 2nd round isn't encouraging. Also, it's hard to get excited about the near future with how the kids have been handled and the roadblocks in front of them. Finally, there's a real chance that Gavrikov and/or Korpisalo won't re-sign, which would open up two holes again.
I think Game 4 was a bit of a turning point and if the Kings hold that lead and go on to win the series, they have a reasonable shot at beating Vegas.
Agreed though that Gavrikov and Korpisalo potentially walking is a real issue and the Kings will struggle to replace them if they do.
Personally, I haven't seen a huge issue with the way most of the young talent has been handled - I see this as a team building long-term, so already competing now is a bit of a bonus and arguably ahead of schedule. I always side with 'overdeveloping' versus pushing anyone into a role they shouldn't be in quite yet.