Judging by Ron Amadeo’s review, it seems that this update is a big refinement across the board. As iOS 7 was to iOS 6, Android 5 is to Android 4.x: a universal revision, aiming to provide consistency and structure across the OS. And, as iOS 7 took cues from Android at the time, Lollipop takes some cues from iOS: the lock screen, in particular, looks like a lightly-skinned version of iOS’.
But who cares? All mobile OSes are basically converging towards the same point, each taking inspiration (and often more) from their competition. Until something brand new in either software or, more likely, hardware comes along to really shake things up, we’re probably going to be seeing more of the same push towards refinement, not revolution. And that’s okay.