Oct. estimates suggest Apple will sell 2.9M Macs this quarter

But given that nearly 50 percent of Mac sales in the three-month frame take place in the month of December, it is still too early to tell with certainty how Apple will perform, Gene Munster, analyst with Piper Jaffray, told investors in a note released Wednesday afternoon. Retail sales data from NPD Group for the month of October suggests that Apple will sell between 2.8 million and 2.9 million Macs in the December quarter; Wall Street consensus is said to be about 2.85 million.

If those estimates hold true, that would put overall Mac sales up 14 percent year-over-year. NPD data for October was up 7 percent year-over-year.

"We expect new iMacs, which launched on 10/20, to help the desktop category rebound in the Dec. quarter," Munster wrote. "NPD data indicates that desktop Macs were up 45% y/y in the month of Oct. In other words, the headwind that existed into the Sept. quarter due to aging Mac desktops has now turned into a tailwind for Mac units in the Dec. quarter."

Munster said that although the October numbers were only up 7 percent year-over-year, that month also included the toughest segment of the quarter, as it was in October 2008 that Apple released its new aluminum MacBook Pros. He believes the addition of new desktop Macs late in October this year will be a key driver in boosting sales as the calendar year closes out.

iPod sales in October were said to be down 11 percent year-over-year. But again, Munster noted that more than half of iPods sold in the December quarter occur during the month of December.

"In other words," he wrote, "we believe the actual numbers for iPod will be slightly better than NPD would suggest."

That means Munster believes that iPod sales for the quarter will top the 19 million to 20 million implied by the current NPD numbers.

In October, Apple reported its best quarter ever, based on sales of 3 million Macs and 7.4 million iPhones. The company's profits rose more than 46 percent in the three-month period that concluded on Sept. 26.

Mac desktop sales fell 16 percent year-over-year in the September quarter, but Munster and others expect that those sales will spike given the release of new iMacs, a unibody polycarbonate MacBook, and faster Mac minis.

Piper Jaffray has maintained its overweight rating for AAPL stock, as well as a $277 price target.