http://www.engadget.com/2011/08/17/3g-macbook-pro-auction-pu...
The bigger issue is probably not having OS X architected to play nice when you're paying by the byte.
Which would never be the case... Right now no Macs come with any mobile data and I somehow still manage to find them useful. If my MacBook had come with 3G it wouldn't be obsolete now that LTE is the rage, the worst thing that could happen is I would tether with another device like I do now.
I also have a Chromebook and I have to say it's nice not to even think about it--you're just online.
There're two reasons why LTE isn't a panacea to cell standards bifurcation and modern cell phones still require fall-back data radios that support EVDO, HSPA, etc.
Apple and telecom? I think the picture is pretty clear.