Long considered a lure for carriers, Apple’s iPhone is now believed to be attracting a full third of those switching providers towards AT&T — the highest ever percentage of converts since the iPhone was released and more impetus for AT&T to keep the iPhone exclusive to them, though that probably won’t happen down the road.

Of the 13 percent of ChangeWave’s panel looking to leave existing cellular providers within the next half year, 33 percent say they will move to AT&T when the time comes versus 24 percent headed towards Verizon.

The figure is a record for AT&T and is even higher than spikes seen in July 2007 and June 2008, both falling roughly in line with Apple’s launch plans for new iPhones in each circumstance. Verizon’s tally itself was a modest 2-point increase, but the carrier hasn’t once passed AT&T in demand since the original iPhone was unveiled in early 2007.

Researchers also observe that AT&T customers are less likely to defect, as 9 percent are strongly considering jumping ship while 11 percent of Verizon customers are less than happy with their experiences.

On the other hand, an alarming stat: The same can’t be said for the actual quality of service. Even as exactly half of respondents using Verizon were “very satisfied” with their service, AT&T could only boast 31 percent and is in a dead heat with Sprint and T-Mobile. 31% isn’t very good, folks, and could be another reason for Apple to broaden their carrier base.