Sources are reporting that Apple may have a lot more than tweaks and enhancements in mind for the existing features in Leopard, for the latest version of the OS – 10.6. In fact, Apple is expected to unify the entire UI, doing away with elements using embossment.

Earlier this month, Daring Fireball's John Gruber wrote that “What I expect is for Apple to make old features look new, by updating the system-wide appearance theme. I’ve made this prediction several times in the past and been wrong, but eventually I’ll be right: it’s time for the last vestiges of the original Mac OS X 10.0 'Aqua' theme to go. Scrollbars and push buttons, for example, remain largely unchanged since the Mac OS X public beta in 2000. My bet says iTunes-style scrollbars everywhere, darker window chrome, and a light-text-on-dark-background menu bar. [...] The name I’ve heard for the new theme: Marble.”

Macnn is citing anonymous sources as saying that Mac OS X Snow Leopard may have a significantly different appearance. Apple is said to be unifying the look and layout of Mac OS X across applications. As a result of this, Aqua themes will be a thing of the past. In exchange, “Marble” is said to be the next look of Mac OS X.

However, many believe there will mostly be tweaks of Aqua, rather than a total overhaul. In all good sense, why would Apple simply give up one of the elements that differentiate its OS so well from others? “The biggest revision may be a 'flattening' of the interface, designed to homogenize its appearance with iTunes and iPhoto,” the report says. However, some may be reluctant to believe that Apple is working to change the look and feel of Leopard, with the latest leaked developer builds showing little to no differences as far as the interface is concerned.