Mark Gurman, reporting that OS X Yosemite will likely be coming at the end of October, alongside:
Also in the cards for the Mac side, sources say, are at least a couple of next-generation Mac lines. Sources say that Apple is finishing up work on both a smaller MacBook with a high-resolution display and a new desktop computer, either an iMac or a standalone monitor, with a 4K resolution screen.
The new MacBook will include a Retina Display that is approximately 12-inches diagonally and it will include a much thinner and slightly lighter aluminum body, the sources said. Apple believes that this new Retina MacBook will be a significant step forward in the laptop industry, and it is currently unclear if Apple will label this machine as a smaller MacBook Pro, a new MacBook Air, or as an entirely new line.
Yes, my mythical perfect last laptop. And a 4K monitor (maybe iMac?) to boot — answering this question (though the “retina” question remains). Hold on to your butts.