In its most recent quarterly report, Apple (NASDAQ:AAPL) reported that it shipped 18% more Mac computers than it did in the same period a year ago, with revenue from those products up 13% in that same time frame. This is in sharp contrast to the company's iPad sales, which dropped 8% on a revenue basis and 9% on a unit basis from the year-ago period. 

With Mac sales booming, it may seem natural that Apple would want to keep that momentum going with updated systems. The question is whether it will. 

One gigantic problem right out of the gate
Computer vendors tend to release new systems when there's something new to promote. One large driver of such system releases is new chip releases, as fresh processors tend to bring performance and power improvements that directly translate into more compelling industrial designs and battery lives.

A good example of this is what Apple did last year with the MacBook Air. Thanks to Intel's (NASDAQ:INTC) new Haswell processors, coupled with hardware and software enhancements on Apple's part, the 2013 MacBook Air offered approximately 12 hours of battery life -- a big step up from the seven hours delivered by the 2012 MacBook Air.

This year, though, Intel slipped on the delivery of its next-generation 14-nanometer Broadwell processors, which were originally slated to launch during the first half of 2014. Without next-generation chips, and with Apple now making the newest version of its Mac OS available on a good portion of the Mac installed base, it may be difficult for the company to offer large improvements over current Mac designs. 

What would a new chip do?
A new chip from Intel would allow for significantly improved performance in a similar power and thermal envelope, significantly improved power consumption and battery life at similar performance, or some optimization point along that spectrum. 

For the next-generation MacBook Air, Apple will likely choose an even lower-power processor than that used in the 2013 model, to enable a fan-less design and potentially a higher resolution display. The MacBook Pro models, on the other hand, are likely to continue featuring higher-power processors in order to improve performance, particularly in graphics. 

When will these new chips be available?
Intel is, per usual, staggering the launches of chips based on its new Broadwell architecture. The first flavor, known as Core M, is intended for fan-less designs and premium tablets and is set to be in systems on shelves by the 2014 holiday season. If the next MacBook Air uses this chip, it has a shot at a 2014 launch. 

Leaked Intel product plans suggest the other chips -- Ultrabook-focused variants and high-end notebook variants -- won't be available until the first half of 2015, ruling out MacBook Pro refreshes until then. 

More clues that new MacBooks and iMacs are unlikely this year
Apple gave a strong hint that it probably wouldn't refresh its MacBook Pro lineup this year when it released slightly speed-bumped versions of the current 13- and 15-inch designs. If Apple were simply trying to clear inventory of current models, it wouldn't be buying new versions of last year's processor designs.

Apple also did a slight refresh of the MacBook Air lineup earlier this year, slightly faster chip and all. 

Furthermore, given that Intel's all-in-one desktop-oriented processors are actually based on the same fundamental designs as its mobile and notebook chips, it stands to reason that the iMac isn't getting a significant upgrade, either. 

What about the Mac Mini and the Mac Pro?
However, Apple can still upgrade two Mac lines: the Mac Mini and the Mac Pro. 

The current Mac Mini is sold with Intel's 2012 Core processor lineup. While these chips certainly aren't slouches, Intel's latest processors offer tangible performance improvements, meaning that if the demand for these systems is there, the Mac Mini could be ripe for an upgrade.

Another, perhaps more interesting, member of Apple's desktop computer fleet is the Mac Pro. Neglected for many years before a 2013 refresh, Apple will have the opportunity to upgrade the design this year to Intel's workstation-oriented flavors of its Haswell processor, known as Haswell-EP.

The current Mac Pro uses the current-generation Ivy Bridge-EP, which is already extremely fast, but a move to Haswell-EP would bring more and faster processor cores, as well as much faster DDR4 memory. 

Foolish takeaway
Apple is unlikely to upgrade its portable Macs this year; if it does, the only one that could have a chance is the MacBook Air -- and even that is up in the air. The action in the Mac will come from the launch of OS X Yosemite, as well as potential refreshes to the Mac Mini and Mac Pro. 

Fortunately, it is unlikely that consumers will be all that perturbed by the lack of new Macs as the current lineup is already compelling.