The Android mobile operating system thoroughly dominates the U.S. consumer smartphone market, while Microsoft's new Windows Phone 7 OS is off to a slow start, according to a new survey by market researcher The NPD Group. And while Apple's share of the consumer market is falling, the iPhone will likely get a boost once Verizon Wireless starts offering the top-selling handset in February.

The NPD report tracks U.S. consumers (18 an older) who bought a mobile phone during the fourth quarter (Q4) of 2010. It doesn't include corporate/enterprise mobile phone purchases, however.

Here's the breakdown for the U.S. consumer smartphone market in Q4 2010:

· Android: 53 percent (up 9 percent from prior quarter)

· Apple iOS: 19 percent (down 4 percent)

· RIM OS: 19 percent (down 2 percent)

· Windows Mobile: 4 percent (down 3 percent)

· Windows Phone 7: 2 percent (new)

· WebOS: 2 percent (no change)

In terms of handset sales, U.S. consumers prefer iOS (iPhone) and Android devices. The top 5 mobile phones in Q4 were:

1. Apple iPhone 4

2. Motorola Droid X

3. HTC EVO 4G

4. Apple iPhone 3GS

5. Motorola Droid 2

Android clearly has the momentum here. As Rubin points out, handset providers at January's Consumer Electronics Show announced plans to use Android to bring cutting-edge capabilities to market, including dual-core processors, 4G speeds, and larger displays. This doesn't mean, however, that consumers will lose interest in iOS. "Android will encounter greater competition this year, however, as Apple's iPhone 4 -- the best-selling handset in the U.S. -- debuts on Verizon Wireless," said Rubin.

As for Windows Phone 7, the much-publicized debut of Microsoft's new mobile OS hasn't resulted in immediate consumer acceptance. According to NPD, Win Phone 7 debuted with a lower market share than either Android or webOS at their launches.

Microsoft "must close the feature gap, offer more exclusive capabilities, work with partners to deliver hardware with better differentiation, and leverage its extensive experience in driving developer communities to increase its app offerings," Rubin said.