Much digital ink has been spilled today freaking out over Gurman’s “Liquid Glass isn’t going anywhere” take. I think we’re all talking about the same thing.
Aqua was around from 2001 to 2014. The Aqua of Mac OS X Public Beta is hardly the same as the one in Mavericks, but it’s still Aqua.
Several good innovations in physical coherence and interaction mechanics went into Liquid Glass. Unfortunately, the first visual execution of the concept has some egregious flaws. But give it 12 years!