Industry analysts expect Apple will refresh its Mac computers midyear to reinvigorate growth, which may have softened somewhat in the first three months of 2012. Last week, for example, Piper Jaffray noted that Apple's core MacBook and iMac lines, which account for half of Mac sales, have not had a meaningful refresh in over a year.

"We believe that [the] MacBook, iMac, and potentially MacBook Air, lines could all be refreshed during the June quarter, which we believe would result in a reacceleration of Mac sales," noted Piper Jaffray analysts Gene Munster and Douglas Clinton in a recent investor note.

KGI Securities analyst Ming-Chi Kuo wrote in an investor note cited in media reports Monday that he expected Apple to launch new laptop products that combine the respective advantages of its current MacBook Air and MacBook Pro offerings.

Intel's Ultrabook push in partnership with a number of laptop vendors deploying new models based on Ivy Bridge -- Intel's latest generation of processors for ultra-slim designs -- is putting pressure on Apple to introduce even slimmer products.

"We note Apple blogs have speculated that MacBooks may be updated with a slimmer body style," Munster and Clinton said.

Kuo believes it is possible that Apple will also move to embrace Intel's Ivy Bridge this year. However, the KGI Securities analyst also believes Apple is likely to discontinue its 17-inch MacBook Pro -- the largest notebook offering in the company's product portfolio.

Apple's Consumer Edge

During 2012's first quarter, the global PC market experienced an anemic 1.9 percent year-over-year growth overall, due to intensified competition for consumers' budgets. "Questions remain on whether low-end systems can attract consumers, as their attention has moved to other devices," said Mika Kitagawa, a principal analyst at Gartner Relevant Products/Services.

On the other hand, Kitagawa thinks vendors such as Apple can be clear winners because of its comprehensive product and service offerings, which have the ability to gain a large part of consumer spending. Though the entire U.S. PC market had a negative growth of -3.5 percent in this year's first quarter, Apple posted 3.8 percent growth, according to Gartner's preliminary figures.

Still, Gartner's preliminary data Relevant Products/Services suggest that Hewlett-Packard led the U.S. PC market during the first quarter of 2012 by posting 6.6 percent year-over-year growth. What's more, HP accounted for 17.2 percent of worldwide PC shipments during the period, maintaining a 4.1 percent over No. 2 global PC vendor Lenovo.

Apple reports its first-quarter results Tuesday. Meanwhile, we asked Kitagawa to give us her opinion about the U.S. PC market segments in which Apple had likely experienced the strongest growth.

"At this stage, I would say that Apple's growth in the first quarter of 2012 was mainly in the consumer market," Kitagawa said Monday. "But we saw growth in the professional Relevant Products/Services market [for Apple] as well."

Apple's Consumer Appeal

Apple's U.S. sales are traditionally strong in the education market, Kitagawa said.

"But the first quarter is not a sales season for education institutions, so we don't think that education market was a contributor of the growth," she said.

The latest data from NPD suggests that Apple's domestic Mac shipments were down 5 percent during the first three months of the year, according to Piper Jaffray. The investment firm's analysts said Apple's global Mac unit shipment growth during the period also could fall short of Wall Street expectations of 14 percent year-over-year growth.

"[NPD data] suggests Mac sales in the range of 4.1 million to 4.4 million, or 9 percent to 17 percent year-over-year growth," Munster and Clinton said last week. On the other hand, the analysts continue "to expect strong iPhone and iPad results, offsetting potential Mac softness."