Thanks for the thoughtful responses so far, peeps. They pretty much confirm what I feel about the fight - people are clamoring for the DC fight because it's an amazing style matchup and he appears to be biggest threat, but nobody is certain what a win over him actually does for Jones when we look at the scope of his career.
I find it really interesting that the guy who most people want to challenge the champion next is still such a mystery/unproven commodity.
I think you have to go back to Brock Lesnar/Randy Couture and GSP/Hughes I for title fights with that dynamic. Cormier is more battle tested than either of those guys were, but when you factor in the experience/weight questions, what you have is an extremely exciting challenger that we'll have to evaluate years after the fight to form a proper judgment on. And that gets a lot trickier if DC moves permanently back to HW after the fight.
At the same time, DC's talent and gifts are so obvious and dynamic that I can't help but think that beating him would be on par or even beyond anything else Jones has done. It's tough. I might just be too used to living in a culture where we have to dissect everything right as and after it's happening.
Or Cormier could KO Jones in a minute and none of this will matter. That's MMA.