The small regional carrier C Spire Wireless made headlines this morning with news that it will join AT&T, Sprint and Verizon Wireless in being the only U.S. operators to offer Apple’s iPhone. The odd man out here, of course, is T-Mobile USA, the nation’s fourth-largest operator who is struggling mightily and hopes to be swallowed up by AT&T. As Sascha Segan wrote two weeks ago, Apple seems to be complicit with AT&T in betting on the death of T-Mobile. I’m firmly opposed to AT&T’s proposed acquisition, but T-Mobile is obviously at a huge disadvantage of being the only tier-one carrier who can’t offer the world’s most popular handset.