Clearly, demand for the handset, the first based on Google’s Android operating system, is far greater than anyone had expected. Earlier this month G1 manufacturer HTC estimated that T-Mobile would sell between 400,000 and 500,000 G1 handsets before the end of 2008. That the company may have already sold three times that amount to customers willing to buy the device without any real hands-on experience suggests the G1 may manage to hold its own against Apple’s iPhone. Apple (AAPL), as you may recall, sold one million iPhone 3Gs during the first weekend the device was on sale.