We all know by now that rumors of Apple's iPhone appearing to a network that isn't AT&T show up all of the time, often coming from a "person familiar with the situation."  Most of the time, however, these rumors often bear no fruit (zing!) and lead nowhere.  Today, however, we've got a rumor with a little more substance behind it.  Chris Anderson, editor-in-chief of Wired, tweeted that a T-Mobile manager mentioned to him that the carrier would be releasing its own iPhone 3GS later this year.

The T-Mobile manager apparently gave no other information, but the little bit that he did share was enough to spur plenty of speculation (and questions).  This definitely isn't the first time we've heard the rumor of a T-Mobile iPhone (heck, at this point we've heard rumors of the iPhone coming to just about every carrier in the nation) and considering that T-Mobile, like AT&T, is a GSM carrier, it would seem to make the most sense.  However, I'm not sure that any T-Mobile employee, manager or no, would be told this information.  The fact that the manager said that T-Mo would be getting the 3GS rather than the new iPhone 4 is also strange.  After adding all of this information up, I'm firmly placing this bit of news in the "Rumor" category.  Scratch that, I'm placing it in the "99.9 percent likely a rumor, but hey, it's fun to speculate" category.  If I were you, I'd do the same thing.

Via IntoMobile, 9to5 Mac, @chr1sa