This rumor seems to come out of nowhere, but the combination of wishful thinking and high-end technology is what makes it so good. AppleInsider says a source told them Apple will integrate 3G access into a MacBook model. Other laptop makers have already introduced the trend into their business and "luxury" models, but Apple is supposedly integrating the card into the display, which saves space and increases performance.
If they do support this, it's likely they'll go with not EV-DO, but AT&T's HSDPA. Why? Well, the iPhone of course.