The G2 Will Repair Itself On Rooting.

"Some excited rooters at the XDA Dev Forum tried to root the [T-Mobile] G2 – namely to unlock the software so they can add their own programs and control the OS – only to find that there is a built-in lock in the G2 hardware that returns the handset to the stock state upon rooting. That’s right: it’s a self-repairing system, like grey goo."