Our sister site Engadget received an invitation for a town-hall event in San Francisco about new Apple notebooks, featuring an image of what could be hinting at possible new aluminum enclosures for 13-inch MacBooks.
tw.apple.pro purports to have images of new aluminum cases for the MacBooks. Judging from the height of the ports (and if the photos are authentic) the new MacBooks could be significantly thinner than their predecessors.
In related news, AppleInsider claims to have confirmed that a widely-circulated spy-shot is indeed one from Apple's next generation of MacBook Pro, but is not fabricated from a single "brick" of aluminum, as 9-to-5Mac said.
The top case, however, appears now to include the ports, rather than having them integrated into the bottom case. (This could make case disassembly easier.) The port arrangement appears to include many more ports on the left side of the bottom case, much like the current MacBook.
Combined with earlier images of the back of the LCD and bottom case, the design retains much of the same look that MacBook Pros (and PowerBook G4s before them) have had since January 2001.
Apple's notebook event is scheduled for next Tuesday at 10 a.m. Pacific time (1 p.m. Eastern).