Those rumors of Apple (Nasdaq: AAPL) upgrading its entire Mac lineup in June didn’t quite pan out, but the Mac maker did give its notebook families a lot of love, with the MacBook Pro, in particular, getting a major makeover with a high-resolution Retina display.

Apple’s popular iMac all-in-one consumer desktop hasn’t been refreshed this year and is overdue. One of the usual suspects that an update is in the pipeline is that supplies at third-party resellers begin to dry up, which we’re now seeing signs of. AppleInsider has noticed that supply at retailers like Best Buy, J&R, Amazon.com, and MacMall are running thin, a possible hint that this overdue update may be imminent.

The same thing happened in April with MacBook Pros, and while the update was a little later than I personally expected, it still proved to be an accurate hint. As far as what to expect inside, Intel’s (Nasdaq: INTC) new Ivy Bridge chips are a lock, and NVIDIA’s (Nasdaq: NVDA) newest Kepler GPUs are also highly likely. Both of these chip transitions have begun and should spread throughout Apple’s Mac lineup, although NVIDIA is subject to supply constraints at manufacturing partner Taiwan Semiconductor Manufacturing (NYSE: TSM) that don’t apply to vertically integrated Intel.

To Retina or not to Retina? That is the question
The real question is whether or not this year’s iMac will feature a Retina display. Dubious Digitimes thinks the answer is “yes,” and even believes that mass production is beginning this month for an October launch. On the other hand, developer of the popular app Instapaper, Marco Arment, doesn’t believe it will happen this year, according to his “multiple sources.”

Panels of this size with such high-resolutions are bound to see manufacturing challenges. For example, a 27-inch display with its pixel dimensions doubled would be a monstrously excessive 14.7 million pixels. That’s over seven times as many pixels as in a full-sized 1080p HDTV, and almost three times as many in the new MacBook Pro with Retina display.

We may only have to wait a couple of months to find out.

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