The HTC G1 has just made a surprise appearance at a Android seminar at the Google Developer Day in London. Mike Jennings (the head of Android development) gave a short presentation of Andoid on what looked to be a production ready G1. The device even sported some crude masking tape which was used to cover up carrier logos on the device. Those who attended the event described the HTC G1 as being "more polished" than the ones we have seen in previous leaked video clips.
Make sure you take a peak at the video of the event.