Android 2.0 may only have been officially announced last week, but don't underestimate the speed of the open-source community. They've already got a basic install of the new OS running on the original HTC Dream (aka the T-Mobile G1); it's not optimized yet, which means the handset chugs along rather than whipping through the pages like we're finding on the Verizon DROID by Motorola, but it's certainly working.
Video demo after the cut
Right now the build also lacks the Android Market and the usual Google Apps, and there's no way of adding new apps to the handset. As we noted when Android 2.0 was launched, it seems Google have borrowed a lot of the third-party concepts from HTC Sense and MOTOBLUR and integrated them more fully into the core OS. That presents a challenge for future iterations of those enhancements, but it's great news for the end-user.
There's a public download here [zip file] but it's really not ready for prime-time yet; this is all a demo to show 2.0 working on the Dream. Arch hacker Cyanogen has promised to deliver a fully-functional build once he has access to the source code, so we're recommend watching the video to whet your appetite and then waiting for that.