Like any developers conference, WWDC 2012 had its highs and lows. Apple introduced some stunning new products and software -- the new Retina-powered MacBook Pro and iOS 6 were particular standouts -- but pro users felt particularly neglected at the June event in San Francisco. Despite a few bumps in the specs, the iMac and Mac Pro were largely untouched. Loyal fans hoping for an upgraded professional desktop would have to wait, even though they've waited about two years for a major upgrade.

Just when all hope for pro Apple users seemed lost, a glimmer of hope arrived in the form of an e-mail from none other than the CEO of Apple himself, Tim Cook.

Our pro customers are really important to us,  Cook wrote to a distressed fan. Don't worry, as we're working on something really great for later next year.

While Cook's e-mail would have you focused on an iMac release date later next year, MacRumors believes this may Apple being sneaky again. The rumors site believes new iMacs could be hitting shelves sooner rather than later.

After tearing apart the new MacBook Pro laptops, Geekbench makers Primate Labs discovered that Apple's previously leaked details about the non-Retina Display 15-inch MacBook Pro matched up exactly with the real specifications, which all but confirms the legitimacy of the original leaked story.

With that under consideration, it makes sense to revisit another benchmark that appeared around the same time -- this one for the iMac. The leaked benchmark for a new iMac described a model called iMac 13,2, which runs on a 3.4 GHz Core i7-3770 quad-core processor with 4GB of 1600 MHz RAM, and operates on OS X 10.8 Mountain Lion, which is the next-gen Mac operating system that won't be released until July. Primate Labs believes this entry is indeed legitimate.

While one rumor coming true doesn't guarantee the other one will, there is a higher-than-normal likelihood that this is the case.

On Friday, Marco Arment, one of the key developers behind Instapaper, published his own theories of when he believes Apple will release the newly-designed iMacs. His blog post was based off multiple sources and Cook's e-mail response to the fan. 

While Arment's theories are interesting and entirely likely, the most interesting part of his blog was actually an update added to the bottom of the page:

I've now heard from multiple sources that while an iMac update is indeed coming this fall, it will not have Retina displays, Arment wrote. Oops. Can't win 'em all.

The Plausibility of an iMac With Retina Display

Arment's core theory centered around the idea that Apple will build Retina Displays into all of its devices, now that it has successfully ported the ultra-high resolution displays from iPhones to iPads, and now MacBook Pro laptops.

Before his ominous update, Arment described a potential timeline of new iMac and Mac Pro release dates.

The iMac has higher margins, sells in far lower quantities, and is under less competitive pressure to keep an aggressive update schedule, Arment said. It's plausible that Apple can start selling Retina iMacs in a few more months. And since the iMac is often bought for shared family use, it's a great product to release right before the holiday shopping season.

Since the Mac Pro is much different from the iMac -- the Mac Pro is sold separately from the display -- Arment believed Apple was delaying the Mac Pro update until later next year because making a stand-alone Retina Display for the Mac Pro would be difficult to mass manufacture. Apple would also benefit by waiting until the spring to capture a lot of buss once the hype over the iPhone settles down.

Arment quickly discovered the issues with such a massive, stand-alone Retina Display. Yes, it's extremely expensive to make and mass produce, but it's implausible for so many more reasons. Remember: Whether you're talking about an iMac or a Mac Pro, the screen you're working with is either 21.5 inches or 27 inches.

First of all, making a Retina-quality display out of a 27-inch Cinema (a.k.a. Thunderbolt) Display is a tall order. But second of all, who needs all those pixels? A 5120 x 2880 panel is a bit ridiculous; even using the full 2880 x 1800 resolution on the new MacBook Pro with Retina Display makes everything incredibly tiny. But thirdly, and most importantly, a large Retina Display screen would require more bandwidth than what today's Thunderbolt ports can handle. (A 5120 x 2880 screen would need more than 21 Gbps; Thunderbolt can only provide up to two channels of 10 Gbps.)

That last issue -- today's capabilities -- is likely why our dreams of a big, beautiful iMac with Retina Display will have to wait. At least until next year.