Welcome, we hope you switch. The G1 isn't quite as polished as the iPhone yet, but it's on the way there. And when it gets there, it'll be way better as the platform is much more open (i.e. lacking restrictions, as in the marketplace) than the iPhone. While for the moment this means there's a lot of garbage to sift through while everyone figures out how to code G1 apps, in the long-run I think there will be much more interesting apps available, and more for free.
Anyway, welcome again. Hope you get a G1 =)