According with MobileChurch, HTC is not planing to launch the new HTC Sense UI any time soon for US T-Mobile Android users.
That’s right, even though The G1 and the MyTouch/Magic are made and developed by HTC, you’ll find it also says Google on the back. Being a Google-branded product apparently precludes the Magic and G1 from using the Sense UI featured on the Hero.
I believe the Sense UI is the catch to buy the Hero, without mention the Adobe Flash support.
I bet there will be some hackers that will help you to install the HTC Hero Rom on the G1 or My Touch 3G