U.S. Mac sales were up 16% year-over-year in the first two months of the March quarter, ahead of Apple’s release of the new MacBook Pro lineup, according to the latest domestic retail tracking data from the NPD Group (http://www.npd.com) — as reported by “AppleInsider” (http://www.appleinsider.com).

The research group says U.S. Mac sales were up 16% year-over-year in January and February of 2011. As noted by analyst Gene Munster with Piper Jaffray, the consensus view on Wall Street is that Apple will report Mac sales up 22% year-over-year for its March fiscal quarter.

While the number is low, it also represents two months before Apple released its new line of MacBook Pros, which arrived in late February, says “AppleInsider.” This suggests that sales may have dipped before the anticipated refresh. Supporting this theory, U.S. Mac sales were up slightly more — 20%– in January, the article adds.

Since international Mac sales tend to have stronger year-over-year growth than Apple’s U.S. sales, Piper Jaffray analyst Gene Munster expects Mac sales to be up between 20 and 25 % in the quarter, which would be in line with Wall Street’s expectations.

The NPD Group also says an increased investment in infrastructure products, from mostly small and medium-sized businesses, propelled total hardware spending up 18% to more than $38 billion in 2010, and a major improvement over the 10% decline experienced in 2009. The biggest hardware investments were made in the computer market.

Revenue jumped nearly 33% to $6 billion, and unit sales increased 27% Even coming off tough comps following the launch of Windows 7 in the fourth quarter of 2009, Q4 2010 computer sales increased by double digits, 14% in units and 22% in dollars, according to the research group.