Apple's U.S. Mac Sales Up 20% in January

Currently, investors expect to see about 22 percent year over year growth in the March quarter, resulting in 3.6 million units. Though U.S. sales were up less -- 20 percent -- in January, Munster noted that Apple has seen faster international growth of the Mac platform.

The company sold 2.94 million Macs in the year-ago quarter, which itself was up 33% over the first calendar quarter of 2009.

January's strong results were presumably driven in large part by strong sales of the revamped MacBook Air introduced last October, and Apple's sales should see another significant bump with the expected release of new MacBook Pros just two days from now.

NPD's data also reveals a year-over-year decline in U.S. iPod unit sales of about 10%, although continuing declines in iPod unit sales have been offset in recent years by the increasing popularity of the iPod touch, which has worked to keep Apple's iPod revenue relatively steady from year to year.