TmoNews has an anony-tip that they'll be firing up their 3G network in those 20+ top markets on Oct. 1. The rumor's fairly squishy, but it's not totally whack—T-mo promised to roll out 3G in major markets throughout the year, plus we'd heard those top markets would be balling along by the end of it. So, even if it's later than October, it won't be too much later. Hopefully. [TmoNews]