Don't let the headlines fool you. If you own a "T-Mobile G1 with Google" or plan to own the "myTouch 3G with Google" you are going to be sorely disappointed.
The crux of the matter falls to the "with Google" addendum to the G1 and myTouch. Remember, Android comes in three distinct variants. The variant that is branded "with Google" is controlled strictly by Google, and cannot be changed. This is the style of Android (version 1.5) that is running on the HTC G1 and on the myTouch 3G. That means no third-party user interface overlays for those two phones, which is exactly what Sense is.
HTC has confirmed this for me in past conversations. The G1 and the myTouch, both available from T-Mobile will not be able to take advantage of this new user interface from HTC.
The one thing to keep in mind is that HTC will make other, non-Google branded Android devices, such as the Hero, which was announced yesterday. These phones can and will run Sense. So, when Peter Chou said that Sense UI can be used on other devices, this is what he was talking about: The Hero, and subsequent follow ups to the Hero that don't have Google branding attached.