I don't know . I saw some charts on a Mac fan website that showed that over the past two years, Macs as a proportion of sales for Apple have fallen very significantly, replaced obviously by billions of dollars of income from iPhones.
From a larger perspective, the migration of apps like iMovie to the new iPhone and the app store in general, combined with cloud computing, point to the end of the age of the PC. The new PC is probably going to evolve to something closer to the iPad and iPhone, Android, etc. type of devices. AVID demonstrated a remote editing over the web application at NAB this year. It isn't that Macs won't be around, but I think that we will continue to see the slow erosion of features, inputs and pro features on Macs because obviously the pros aren't where the big money is, it is the masses buying iPhones, iTunes and the App store that are driving Apple forward.
This trend is not limited to just Macs either. People who have been trumpeting that the age of the PC are coming to a rapid close say that it is all PCs, not just Macs. It is true when you think about it. Who needs computers anymore when you can communicate via phone, text, Twitter with your handheld device and you can consume media on your small little iPad type of device? Those two operations cover probably 95% of all PC users. Doesn't a Mac Pro tower with its massive size and weight, tethered to huge monitors begin to sound somewhat like an anachronism?
Not saying that PC/Macs are going away in the next year or two but the writing is plainly on the wall that the era of the PC is drawing to an end except for a small contingent of users who may find that the machines that they need may no longer be made.
Perhaps we will eventually become like Cuba with the classic American cars, we will all be nursing pristine antique G5s and Mac Pros because Apple stopped making them. A huge black market for parts, software and manuals will spring up on Ebay to keep them still humming? Shades of my days with the Amiga! That was another machine that users wanted to keep going more than the manufacturer(s) did.
I do see the ability to control and manipulate media will become more and more ingrained in consumer and prosumer products like the new iPhone. At some point, most everything that takes big iron and lots of third party software to accomplish will be able to be done by anyone with a small, portable and cheap device. Moore's Law still applies and doing almost everything in software will just keep on evolving. Remember ICE cards for your Mac and AE plug-ins? Seems like ancient history but it was only, what, ten years ago