Appleinsider cites one of its sources as claiming that future Apple notebooks may feature an option to include built-in 3G wireless.
While such features have been present in the PC industry for some time, Appleinsider believes that Apple will do a better job of implementing the chip, placing it in the display and away from the logic board to minimize electromagnetic interference and maximizing potential signal strength.
Which technology Apple will adopt is unclear at this point. HSDPA, supported by AT&T (and other global carriers), seems to be a logical bet regarding Apple's work with the company with the iPhone. However, with Appleinsider's source unable to identify the technology to be used, this tidbit remains speculative.
As a historical note, Intel's Santa Rosa platform originally specified having such a 3G HSDPA card for notebooks, but such plans were later scrapped, citing lack of a good business case.