HTC sources say they expect to sell 1.5- 2 million Google Android OS phones.
The T-Mobile G1 will be released by T-Mobile on October 22 and they predict to sell 400,000 - 500,000 in Q4.
It is also believed that Motorola is getting ready to launch its own Google Android OS phones.
Although the G1 does not have all the functionality of the iPhone. It is hoped that open source developers will create applications.