Another week, another analyst weighing in on the iPhone's future.

This one comes from Brian Marshall of New York equity researcher BroadPoint AmTech (now part of Gleacher), who predicts that because of a deal AT&T cut with Apple for the iPad 3G, the U.S. telecommunications giant will continue to have carrier exclusivity for the iPhone until at least 2011.

His reasoning goes like this: Apple hasn't been happy with AT&T's network performance for the iPhone. AT&T wanted to remain the exclusive U.S. carrier for the Apple phone, keeping it out of rival Verizon Wireless' hands. So it offered a generous and recurring monthly data program for the iPad.

While we're taking this with an ice cube-size grain of salt, we can see the reasoning. AT&T threw Apple a bone that made the 3G iPad even more desirable than it was.

One thing, though: another firm, Global Wireless Solutions, released a study this week comparing all the major wireless providers in New York City. It found that both Verizon and AT&T were about 99 percent reliable, with throughput up to 20 times what they offered five years ago.

Assuming that GWS' data is accurate, and that AT&T did actually make the iPad deal to keep the iPhone away from Verizon a little bit longer, maybe that deal doesn't matter--at least for iPhone owners in New York.

Originally posted at Crave