In a statement this week, Microsoft said that "initial supplies are tight" and that some customers have been "disappointed to learn their local stores are already out of stock." The company added it was working with partners to bring more phones to stores in the coming weeks. The devices, however, are also available online.
Of course, keeping supplies more limited to start can help create the impression of high demand even if sales aren't through the roof, so it's hard to read too much into that statement. Apple has typically set the bar for strong launches, with 250,000 units sold the first weekend when the first iPhone went on sale in July 2007; 1.6 million iPhone 3GS units were sold in its first week in June 2009.
The Motorola Droid got off to a good start with 250,000 first-week sales last November, helping to ignite the spread of Android-based phones. By contrast, Google's ill-fated, directly sold Nexus One sold just 20,000 units in its first week.
With multiple Windows Phone 7 launches this week, it's hard to make an apples-to-apples comparison with other smartphone debuts. But it's safe to say sales of the new Windows-based devices will fall somewhere between the extremes of the iPhone 3GS and the Nexus One. But after talking up its upgraded mobile platform for nearly a year, and its smartphone stumble with the Kin, Microsoft will badly want to report healthy early sales for Windows Phone 7 devices.
So if initial results are solid -- as in the hundreds of thousands -- expect Microsoft to blast out the numbers. If not, expect the company to remain coy, making general statements about being "pleased" with results and a strong demand for its new phones.