Image source: Apple. 

Fans of Apple's (AAPL 0.46%) Mac personal computers are about to see a very long overdue refresh, according to a Bloomberg report that cites "people familiar with the matter." The report claims that the company's iMac desktops, MacBook Air, and MacBook Pro lines will all be improved. 

These new Macs are expected to see the light of day "as soon as late 2016."

Let's take a look at what this refresh should mean for Apple's business, as it's been a while since the company released significant updates for many of its Mac product lines. 

Setting up for nice year-over-year comparisons

Throughout Apple's fiscal 2016, the company's activity around the Mac was limited. It released upgraded iMacs in October 2015 and quietly refreshed the 12-inch MacBook in April, but the company's popular MacBook Air and MacBook Pro lines were left untouched. 

Apple doesn't break down the mix of shipments of its different Mac lines, but I would imagine that the MacBook Air family is a significant volume driver for the company. The MacBook Pro likely ships in meaningfully lower volumes than the MacBook Air, but the average selling prices on those systems should be higher, magnifying its revenue and gross profit dollar impact to the overall Mac business. 

This had the effect of making Apple's Mac lineup a little bit "stale," particularly as many of Apple's competitors in the personal computer market haven't exactly been standing still. 

All told, Apple's lack of action on the Mac side of things seems to have had a real impact on the performance of the company's Mac business -- it's seen double-digit unit shipment declines in two of the last three quarters .

To be clear, Apple's Mac business isn't small, even relative to Apple's gargantuan revenue base. In the company's fiscal 2015, it brought in more than $25 billion in revenue -- good for more than 10% of Apple's roughly $234 billion in revenue that year. 

The good news is that if Apple can roll out a bunch of new Mac products early on in the current fiscal year, the company will be setting itself up for growth in both unit shipments and average selling price.

What does Apple have planned?

Bloomberg makes it clear that Apple has a lot of interesting stuff cooking with its upcoming Mac products. The iMac is expected to get newer graphics processors, though it's not clear what other upgrades, if any, these systems will get. The current iMac models are already quite powerful and use modern hardware, so upgrades here would be nice, but they're not sorely needed as they are elsewhere in the Mac lineup. 

Apple is also reportedly planning to launch "tweaked MacBook Air devices" with "multi-functional USB-C port technology." In addition to the enhancements that Bloomberg reports are incoming, it seems reasonable for Apple to update both the industrial design of the MacBook Air, whose current generation design is quite dated, as well as the display technology used in the device -- the display technology on the current models are nothing short of woefully behind the times.

Beyond design and display enhancements, I would expect Apple to utilize next-generation Intel (INTC 1.91%) Skylake processors, which should help performance and battery life. The current MacBook Air models use chips based on Intel's older Broadwell architecture.

Finally, Bloomberg says that a "thinner MacBook Pro with a flatter keyboard is also in the pipeline." This new MacBook, Bloomberg says, will come with a "digital function key display above the keyboard" -- the OLED touch bar that KGI Securities analyst mentioned a while back.

These all sound great...

Although Apple has let many of its Macs go stale, it seems that what the company has planned is both significant and, frankly, exciting. It's not clear why it's taken so long for Apple to finally put together a comprehensive refresh of some of its most important product lines, but investors should hope that this phenomenon doesn't repeat.