For whatever it's worth: I have a four- or five-year-old Kensington lock that works just fine with my daughter's brand-new Aluminum MacBook. I suppose the new locks might be made differently, but it seems unlikely that the shank which protrudes into the computer would have been shortened enough to prevent it from reaching through the MacBook's Aluminum sidewall — the only reason I can think of why a new Kensington lock might not work with a MacBook. There are still plenty of plastic-shelled notebook computers out there, and a plastic sidewall thinner than the MacBook's aluminum shell wouldn't provide much resistance at all against an effort to pull the lock out without unlocking it. So I suspect Kensington's lock will still reach through the MacBook case.