With two months gone since Microsoft launched Windows Phone 7, the company has finally started to address the big question about the new smartphone platform: how well is it selling? In an interview with Microsoft vice president of business and marketing for Windows Phones Achim Berg published in a press release earlier today, Microsoft claimed that phone manufacturers had sold more than 1.5 million Windows Phone 7 handsets.

Though that's not quite the answer that people want—what we really want to know is how many handsets have made it into users' hands, not been sold to the cellular networks—it's still a strong indicator that phone networks and OEMs alike are supporting Windows Phone 7 in a big way. Even if half those phones are sitting in storerooms or on shelves, that's still three-quarters of a million phones sold to actual customers, and for a brand new platform, that's not a bad record at all. Given the difference in sales models between iPhone, Android, and Windows Phone 7, exact comparisons are always a bit hard to make, but by means of comparison, Apple took 74 days to sell its first million iPhones, and T-Mobile in the US took about six months to sell one million Android-powered G1s.

While there are still some questions about the strength of the operating system's launch, it's becoming clear that the Windows Phone 7 application store, Marketplace, has gotten off to a very strong start indeed. In the two months since opening, the Marketplace now boasts in excess of 4,000 applications. It took five months for Android's Market to reach 2,300 applications, and fifteen months for webOS's App Catalog to hit 4,000 applications. Even the iPhone App Store, which had the advantage of being launched a full year after the iPhone, didn't grow this quickly; two months after its release, it had fewer than 4,000 applications available.

At just two months old, it's still early in Windows Phone 7's life—and as Berg acknowledged in his interview, Microsoft is in the smartphone race "for the long run." It will be months or years before Windows Phone 7's success can truly be ascertained, but it looks like it has hit the ground running.