We hear so many iPhone-Verizon-tomorrow-OMG rumors that our nation's brave also-ran carriers hardly get a word in edgewise. While Sprint remains a total longshot, T-Mobile USA is an interesting proposition for the mere fact that it's a GSM network, though its 1700 / 2100 3G network remains ostensibly incompatible with the iPhone 4's existing radio. According to Cult of Mac, a "highly placed source" at T-Mobile let it slip that they've got an 80 percent chance of getting the iPhone in Q3. Now, that's an oddly specific number, and we have no idea what it's contingent on, or how much exactly this source knows. Basically, we don't know a lot here. Of course, the biggest evidence of this possible T-Mobile coup remains the statement from Deutsche Telekom's CEO in March, saying that the USA branch is hoping to get the iPhone later this year. We really don't know who or what to believe, but we do know one thing: if Apple decides to sell a T-Mobile USA iPhone, there's an 80+ percent chance it will tell everybody.