WP7 manufacturers have shipped 1.5 million handsets to carriers and retailers

Mr Berg says that the WP7 manufacturers (LG, Samsung, HTC and Dell) have shipped 1.5 million handsets to carriers and retailers so far. How many of them are actually sold to end customers is probably a different story, but he says the platform is meeting Microsoft's expectations, and they are in the mobile industry for the long run.
The good news for Windows Phone 7 owners is that Microsoft is determined to improve on the mobile OS with a dynamic pace. The first update should come around February, and a new version of WP7, codenamed "Mango", is being prepped for later next year. By that time Windows Phone 7 should have enough critical mass of handsets to attract some serious application development, thus growing its Marketplace exponentially.
source: Microsoft