I'm willing to bet one of them gets us even closer to the worldsoul at the heart of the planet.
Thankfully, we don't need to know for a good long while...
- - - Updated - - -
Hear hear! The thing I am REALLY happy about is that delves have an endgame progression system for open world players. I do raid with a team on my main character (and occasionally do an M+ or two), but I have a number of alts and all I do with them is open world content because it's fun. And the progression system will eventually get us close to heroic raid loot (which is perfectly fine, we are long past the days when someone else's gear has any impact upon you whatsoever.) So, win/win.