In the world of Operating System User Interfaces, Apple has long been considered king of the hill when compared against Microsoft Windows and various Linux and UNIX distributions.  Aqua, the GUI introduced with OS X has long served Apple and helped to keep the company ahead by having the "cooler" interface.  But Aqua is starting to grow a bit old.  Sure it gets tweaks and additions now and then, but we've had Aqua as long as Windows XP has been out, and with Vista moving to the new (in some cases very mac-like) Aero UI, maybe it's time for Apple to give its system a facelift.

That facelift is exactly the rumor being kicked around the Apple Rumor Mill online as speculation starts to ramp up in advance of the January Macworld 2007 conference, where Leopard (OS 10.5) will be shown off in its near-final form.  Speculation currently points at a new, flatter, black glassy UI to replace the bright whites, greys and blues of Aqua.  This would keep with the recent GUI changes to applications like Aperature, iTunes and iPhoto which have moved to a darker, sleeker look.  They're calling the new GUI, "Illuminous."

Will this mean a new default look for Macs in 2007?  We won't have to wait long to find out.