I've been clicking settings, about, check for update every day or so and finally it's coming down. Very exciting. I had a brief play with a Google staff member's phone the other day, will report back in a couple of days.
I used the G1 for about a week after I got it but reverted back to the much smoother iPhone. It will be interesting to see what Cupcake is like.
More news as it comes to hand.