If you have seen any of the hoopla in regards to the T-Mobile G2 not being able to be rooted. Or more specifically, how the G2 can be rooted but it will restore back to an original non-root state after the next boot which in the end means it can only be rooted temporarily — here is the official follow-up statement from T-Mobile.
Code-Level Modifications to the G2
As pioneers in Android-powered mobile devices, T-Mobile and HTC strive to support innovation. The T-Mobile G2 is a powerful and highly customizable Android-powered smartphone, which customers can personalize and make their own, from the look of their home screen to adding their favorite applications and more.
The HTC software implementation on the G2 stores some components in read-only memory as a security measure to prevent key operating system software from becoming corrupted and rendering the device inoperable. There is a small subset of highly technical users who may want to modify and re-engineer their devices at the code level, known as “rooting,” but a side effect of HTC’s security measure is that these modifications are temporary and cannot be saved to permanent memory. As a result the original code is restored.
Bottom line, this is only affecting a small subset of users, granted they are vocal users but T-Mobile does have some good points. That said, I would still think that someone will eventually find a workaround, though it just means the job will be that much harder and take that much longer.