Just in time for their big Android announcement on September 23, T-Mobile announced Thursday that they will expand their 3G service by mid-October to 8 additional markets, including Atlanta, Chicago, Los Angeles, Orlando, Philadelphia, Sacramento, San Francisco and Seattle. This brings the total to 21 cities with another 6 cities (Birmingham, Denver, Detroit, Kansas City, Memphis and Tampa) expected to be added by the end of the year. Looks like they’re right on track and not wavering from their expected launch dates. With Android right on the horizon and 3G coming in on schedule, it looks like things are coming up roses for T-Mobile right now.