A few months ago we ran a rumor in which Steve Jobs had written a reader promising that Apple was working on iPhone tethering for 3G laptop browsing. Now, according to a MacBlogz, a reliable source from inside AT&T has informed them that iPhone tethering is being delayed because AT&T isn't prepared to meet the 3G demand. According to the source:

Regardless of how many billions of dollars AT&T pours into their 3G network, it hasn’t been stable enough to handle all you iPhone users

They added that AT&T Blackberry tethering is a different beast, as Blackberry users haven't caused nearly the strain of iPhone users on AT&T's 3G network.

AT&T, on the other hand, routinely insists that they leave all service features up to the hardware manufacturers.

Given that AT&T has has taken plenty of bumps on the chin regarding iPhone data, and given that iPhones have sold even better this year than projected, it's not such a stretch to believe that AT&T might be playing it safe for the time being and handling their 3G network with care. [MacBlogz]

Send an email to Mark Wilson, the author of this post, at mark@gizmodo.com.