I'm willing to bet the farm that the world's first Android-powered phone is called T-Mobile G1. I've been watching all the domain names starting with T-MobileG1.com through T-MobileG5.com over the past week. Up until today, there wasn't any Name Servers attached to T-MobileG1.com and G1Phone.com! By performing a simple whois lookup, it lists ns1.logicworks.net and ns2.logicworks.net as the Name Servers.
So, what's the connection? T-MobileAtHome.com, Sidekick.com, T-MobileShadow.com, among others is all hosted by LogicWorks. By adding the Name Servers to the domain T-MobileG1.com, I believe it's only a matter of time before T-Mobile officially announces the G1 Android phone.
Another conclusion I've arrived at: T-Mobile plans to offer at least four more generations of gPhones after the G1.