The company now predicts total PC shipments for 2009 will be slightly up on 2008, with a return to strong growth in 2010 that will last at least to 2013.
But the recovery - such that it is so far - isn't evenly spread.
IDC's predicting a permanent shift away from desktop models, with sales having already peaked for the foreseeable future.
The worldwide mix for 2008 was 144.9 million desktops, and 142.7 million portables for a total of 287.6 million units.
For 2009, IDC is estimating 126.2 million desktops and 165.2 million portables, ie 291.4 million units overall.
That means a 1.3% increase in total units, but a 15.8% lift in portable units.
Many of those portable units were mini notebooks (including netbooks) - that category grew by 37% from 2Q09 to 3Q09, and doubled its share of the consumer portable market from 14% in 3Q08 to 28% in 3Q09.
While prospects for that hardware segment appear limited, commercial purchases are set to boom - see page 2.
That said, IDC expects new ultra-thin portables will choke the demand for mini notebooks, although the category will continue to grow in 2010.
"Beyond stabilising their business, PC vendors are trying to position themselves for gains as the market recovers. We're seeing aggressive promotions and expect innovations leveraging new technologies, including ultra-thin designs, touchscreens, and LED panels," added Chou.
AppleInsider notes that IDC's figures show Apple achieved year-on-year growth of 16.4% for the quarter. Chou told AppleInsider "they outperformed the total market quite well".
Although the total growth in the quarter came from the consumer market, IDC reported a slowing in the decline in commercial PC sales, and expects the sector to return to growth in 2H10.
"An ageing installed base of PCs to replace, along with government aid and declining average selling prices are key ingredients in a recipe for resurgence of PC shipments into the commercial market segment," said Richard Shim, research manager for PCs at IDC.
"The combination of a recovering commercial market and a healthy consumer market will lead to double-digit shipment growth through 2013," he added.