If you’re a Mac lover, chances are that one of your favorite things about OS X is the incredible graphics engine running behind-the-scenes. Aqua, as it’s affectionately referred to in the Mac community, was the first GPU-driven graphical user interface that hit the market, and paved the way for Vista’s upcoming Aero UI and Linux’s maturing Xgl interface. With Vista having just seen release (at least for businesses), this marks the first time since 2000 that Windows has even been in the same ballpark, appearance-wise, with OS X, and rumors are flying that Aero’s shiny appareance has Apple nervous.

How nervous? According to Apple Gazette, nervous enough to replace the 5-year old appearance of OS X with a new interface called Illuminous:

“Apple Gazette has received a tip from an apple insider that the Mac OS Aqua User Interface will be replaced with a new UI named Illuminous. The source goes on to say that we will see a demonstration of Illuminous at Macworld 2007.”

Of course, this being merely a rumor at this stage, details are extremely sketchy:

“What will Illuminous look like? ThatÂ’s anybodyÂ’s guess at this point, but we might be seeing some hints of what Illuminous holds in the recent release of iTunes. We will keep you posted as more information becomes available.”

I personally wouldn’t put too much stock into this rumor just yet. Most agree that Aero is nothing more than a hungier, less well-implemented ripoff of Apple’s Aqua, and that Microsoft went overboard in trying to make the interface look better than Apple’s baby. While the recent iTunes 7 UI was substantially different than it had been previously, it alone isn’t a concrete indicator as to what Apple might have in store; for all we know, it could be the next visual update to Aqua. However, if Apple really is considering such a move, it should be interesting to see if they can finish and implement such an overhaul by Leopard’s Spring ‘07 release date. So, keep your eyes on Apple, but I personally am not ready to declare Aqua yesterday’s news just yet.