Just a few days before the official launch date of October 22nd, T-Mobile's presales of the new Google Android G1 phone have reached 1.5 million.

Existing T-Mobile subscribers have priority on preordering the phone, and it's expected to make a difference, since T-Mobile's initial production order at HTC was for just 500,000 phones.

The majority of orders come from within the United States, followed by the UK, where 25,000 people have signed up in line, but haven't committed to a purchase yet.

The G1 will come with Google Search, Maps, Calendar, Talk, Gmail and YouTube preinstalled. Applications will be made available on the Android Marketplace, a service similar to the one offered by Apple, but that doesn't charge a fee.

Currently, the #1 smartphone in the US is Apple's iPhone, which holds 28% of the smartphone market. Although yet unknown, it is estimated that Apple has sold more than 12 million iPhones up until today, after seeing a big increase with the release of the iPhone 3G.

Despite all the buzz generated by Android, the search giant Google has still made a deal with Apple to enable people to directly target ads to the iPhone using the AdSense program.