Well, at least not officially. A home-brewed version of Sense has already been leaked onto the web, allowing users of the HTC Magic, Dream and T-Mobile G1 to unofficially upgrade their phones. The ROM apparently originated at HTC and was modified by two Italian hackers to work on the older devices.
Aside from the nice graphics there are a number of glitches to be found, however, like non-compatibility with auto-screen rotate and apparently Wi-Fi and Bluetooth don't work at the moment. Flash functionality and overall performance seems a bit laggy on the G1, too.
Needless to say, most users are better off keeping their current Android installation, but the curious types can still head to the Android HD Blog (translated) for instructions on how to get the new interface up and running on their device. You can also check out a hands-on video with HTCs Sense hacked onto the G1 after the jump.