If the story that gizmodo is carrying is right, then I have another reason to be happy with not going with T-Mobile G1 Android.
According to a customer who took the G1 to UK and coming back to find a bill $102.85 in data roaming, with data roaming, data sync and 3G were turned off.
A T-Mobile customer service supervisor has revealed that T-Mobile G1 always access internet, even if those services were turned off!
May be to tell T-Mobile where you are! Read more at gizmodo, where there is already a bunch of comments. And I learned that Gizmodo people are apple fanboys, just from a single comment