Chalk this one up to the rumor mill for the time being, but rumbles on the street indicate that T-Mobile might be preparing to flip the switch on it’s national 3G network on the 1st of October. According to the source, the carrier will bring 3G data coverage to its 27 top markets, including the cities that have already benefited from the recent soft launch of the faster mobile data protocol. Sure, it’s a bit later than the other 3 major US carriers, but if T-Mobile uses their impending launch as an excuse to bring us some tasty new 3G-capable handsets, including their upcoming Android device by years end, we wouldn’t be disappointed in the least. We’ll work to dig out some more details on this one, but keep your fingers crossed, folks.