AT&T chairman and CEO Dave Dorman yesterday didn't miss his chance to cozy up with his new buddies at Cingular at the expense of some old ones. At SBC and AT&T's acquisition announcement, Dorman made it clear that its new mobile virtual network operator--if you could call it that anymore--would be launched over Cingular's network, not Sprint's.

While I could go on and on about the ironies in AT&T being reunited with its wireless namesake, which recently merged with Cingular, there's a much more significant issue to pick at here. Namely, Sprint's ability to get AT&T's enterprise customer base integrated into a wireless network. Sprint is the only carrier to date to commit to deploying an IP multimedia subsystem (IMS)-based core, which, though not the stated reason for AT&T opting for Sprint for its new MVNO AT&T Mobile, certainly has to be a hefty incentive for AT&T to choose its old CDMA competitor.

From what little info AT&T has released about its wireless plans, it's eschewing the consumer wireless model entirely and targeting its wireless service directly at the enterprise. But unlike consumers, who seem willing to keep their wireless and wireline services in their separate vacuums, enterprises are expecting a certain amount of integration between their wireline and wireless networks. Cingular, like most of the nationwide players, can supply that integration to a degree, but Sprint's IMS plans could bring that integration to astonishing new levels--linking the enterprise office network with the wide area wireless network over the same IP platform. Of course, IMS's full capabilities may be more conceptual than concrete right now, but few would argue that the current duct-tape and superglue integration attempts today are any better.

Like most carriers its size, Cingular will almost definitely layer IMS into its core at some point. In fact, it's entirely possible Cingular has some super-secret IMS plan in place that could match Sprint's deployment timeline. Cingular may have not seen it fit to announce those plans yet. I doubt it, though. Cingular has its hands full bringing AT&T Wireless into the fold (though Sprint, admittedly, will face an even more complicated network integration next year), and the UMTS networks that would use IMS's new capabilities are a year beyond Sprint's deployment of 3G. Meanwhile, Sprint has a contract in place, has named a vendor and scheduled its launch in 2006. And it already has the advantage of a mostly IP-based core in place, to boot.

To be fair, AT&T doesn't have a lot choices, if AT&T does go through with its MVNO launch this year as Dorman insists. It can't very well beg off the pet carrier of its new owner SBC. It will have to dump Sprint, but in the process may set its enterprise wireless ambitions back a year or two.

E-mail me at kfitchard@primediabusiness.com.