But the iMac refresh should result in a short-lived bump in desktop sales, said Stephen Baker, an analyst with retail research firm NPD Group.
"They almost always get a bump, but the size of it depends on the time of year," said Baker. "Over the last couple of bumps, desktop sales have gone from negative year-over-year to positive for a couple of months."
Desktop sales bumps typically aren't as long-lasting as Apple's updates to its notebook line, Baker observed.
"In desktops, it's a very short bump cycle," said Baker. "There should be a big increase this May over last year's May, and in June it will be pretty close to the trend levels. By July, it will be back to the negative year-over-year."
But both Gottheil and Baker believe that desktops still have their place.
"They definitely remain an important part of the computing ecosystem," said Baker. "They're the most expandable, they generally have the fastest parts."
Most households have walked away from having multiple desktops, but the larger machines are still the communal computer, said Baker. "Notebooks are personal, tablets are personal, phones are personal, but desktops are the computing device that everybody can share," he said.
Baker noted that all-in-one Windows desktops -- the configurations that mimic the iMac in may respects -- have been posting solid gains, in part because some of them support touch, something that Apple does not.
"Touch just doesn't work on a vertical screen," said Gottheil. "HP has solved that with a screen that moves to a nearly flat position."
Gottheil doesn't expect Apple to copy HP's TouchSmart design. "A touchscreen is for a different user base, at a different time and place," he said.
Last October, Apple CEO Steve Jobs dismissed touch on desktops. "Touch surfaces don't want to be vertical," Jobs said. "It gives great demo but after a short period of time, you start to fatigue and after an extended period of time, your arm wants to fall off. It doesn't work .... It's ergonomically terrible."
The new iMacs are available immediately at Apple's retail stores, some authorized resellers and via the company's online store. On the latter, the new desktops will ship within 24 hours of ordering.
Sign up for CIO Asia eNewsletters.