I know this might sound a bit crazy. But in John Gruber's recent post, he remarked: Its faster (seemingly way faster, far faster than the mere S tacked onto the end of its name would imply). Theyre calling it desktop caliber performance, and I dont think theyre exaggerating. Now that theyve gone 64-bit, Ive got to start wondering about ARM-based MacBooks in the near future. I have been trying to understand why Apple's delayed the new rMBP for so long. The MBA's have been out for a long time now. I have one -- the battery life is amazing. Why might Apple be waiting on Haswell? Well, maybe because it doesn't provide such a great benefit for a "power" machine. That's to say, adding Haswell won't give a big benefit where most "pro" users really want: in computing power. It will only give about a 10% improvement for most users. So besides the "problem" of the computer line not having the latest-and-greatest parts, the rMBPs are, as we all know, great machines as they currently stand. Perhaps Apple sees that there isn't a huge upside to upgrading the computers and is working secretly on using the new 64-bit ARM systems-on-a-chip that are specifically engineered for Mac OS X -- i.e. taking particular system commands that are normally executed in code and hard-coding them in the chip, as they have been doing with great success in making iOS way faster on the mobile devices -- and are planning to ship a Mac with an ARM chip alongside a dGPU.