Update: as noted in the comments, looks like I was right. It now says (italics are mine):
Every new Mac features powerful dual-core or quad-core Intel processing, the world's most advanced operating system, and more.
Ever-diligent AppleInsider noticed that the Apple Store page for Adobe's Creative Suite 3 says:
Every new Mac features powerful dual-core or quad-core Intel processors, the world's most advanced operating system, and more. Build your Mac to your exact specifications, or start with our recommended configurations that are optimized for Creative Suite 3.
Could this mean that Apple will be releasing Macs with quad-core CPUs soon? That's one explanation. Another would be that the distinction between a quad-core Mac (with two dual-core CPUs) and a Mac with one or two quad-core CPUs is lost on the Apple Store copy writer. Or Apple may want to sell a Mac with a single four core CPU rather than dual dual-cores like the current Mac Pro.
Many people seem to think the move to octo-core is a no-brainer. I'm sure there will be a Mac with eight cores in it at some point in the future, but adding cores is far from a magical panacea that makes performance effortlessly go through the roof. There are two reasons for this: in order to keep the additional cores filled with instructions and data, ideally the bus and memory speeds should go up along with the number of cores. Better caching and software tricks can help here, but at some point, a task or set of tasks will be bus-bound rather than CPU-bound and extra cores won't add more performance.
The other issue is the software. There are two ways to gain performance from extra cores: by running more stuff simultaneously, or by splitting one task up into sub-tasks that can run on different CPU cores in parallel. The former is what happens on servers, where each core can tend to a different request. On desktops, the move from one to two cores made multitasking a more pleasant experience, but few people run so many applications at the same time that four or even eight cores increases performance for software that isn't multi-core aware. Fortunately, a lot of (Apple) software is multi-core aware these days, so encoding video, rendering image effects and the like goes faster as the number of cores goes up. However, the application writers are going to find it harder and harder to split the work their applications have to d/ into smaller and smaller pieces, and the overhead of managing the parallel operation will only increase.
Bottom line: in a few years, a "core myth" could be filling the shoes of the only recently abandoned gigahertz myth—for now, I'll be salivating over the prospect of imminent octos like everyone else, though.