If you were hoping to make any modifications to your T-Mobile G2, my apologies. Because the phone apparently ships with a rootkit that will override any changes you make to Android and reinstall the original firmware. That ain't right.
According to the New America Foundation, "one of the microchips embedded into the G2 prevents device owners from making permanent changes that allow custom modifications to the the Android operating system." The full 40-page blow-by-blow of the Dev Forum's thwarted attempts can be found here.
Between this and Motorola's Droid X eFuse kill switch, there's an unsettling - and growing - arrogance. An attitude that says you may have just paid for your phone, but you don't own it. Because if you truly owned it, you'd be able to modify it however you pleased. It's like buying a car and being told you can't buy new Bridgestones a month later. Or more relevantly, as NAF points out: it's like installing Linux on a Windows computer one night and waking up to find Vista back in place.