Almost a decade ago, back in May, 1999, Apple released the PowerBook G3, having a pretty common design, and made of plastic. Only two months after it, the "Clamshell" iBook hits the market, targeting a different group of consumers, but with a very interesting design. Both were retired in 2001, with the iBook being pulled back from the market about 8 months earlier than the PowerBook G3.
With the PowerBook G4, released in September, 2001, Apple started using metal in the notebooks, since this notebook was primarily built out of titanium alloy. The iBook line used plastics for the G3 and G4 generations, and the first MacBook, introduced in 2006, still used plastic, while the PowerBook G4 was refreshed in 2003, with a new aluminum case, and since then, we had the beautiful shiny metal look we all know.
Now, moving into the present, some spy shots that look pretty bad to me, appeared on a Chinese blog on Saturday, and various people familiar with the ongoing MacBook development confirmed this is an authentic next-gen MacBook Pro case. To be honest, I don't think we're going to see a major design overhaul, but since the iPhone 3G had its look and feel slightly improved, leaving the innards aside, I guess that's what we should expect from the MacBook line, too.
There are plenty of rumors regarding the changes to the next-gen MacBooks, including the adoption of aircraft-grade aluminum and stainless stele, to make it all more eco-friendly, as well as the introduction of oversized trackpads and matte black portions of the keyboards.
I know this may not be much, but we'll surely get more details as soon as the iPhone 3G madness fades away. After all, what could be better for Apple then keeping us busy? First, the iPhone 3G, after a few weeks, the new MacBooks, then...who knows what else!