Apple has been busy releasing swaths of new mobile hardware this year, including the iPad, new notebooks, and most recently, the iPhone 4. Apple did manage to squeeze in a revised unibody Mac mini earlier this year, but a couple new pieces of information suggest that new iMacs and Mac Pros could be showing up soon.

A report from AppleInsider indicates that Apple is clearing the channel of current iMac models. Distributors and resellers are supposedly being told to not expect any additional new stock and to sell through the stock they currently have on hand. The updated iMacs are expected to ditch the Core2 Duos used in lower-end models for Core i5 and—in the lowest-end models—Core i3 processors.

Additionally, MacRumors reports customers around the country have discovered that Mac Pros are no longer available to reserve for pickup at some retail locations. This suggests that inventory is shrinking, and may be a sign that the long (and we mean long) overdue Mac Pro update is nearing release. Apple hasn't released a new Mac Pro in nearly 18 months, though the update cycle for the workstation averages about 8 months.

These new desktops are expected to feature updated Intel processors, much faster graphics cards, USB 3.0, and perhaps a faster version of FireWire. AppleInsider also suggests that Apple has test prototypes in its labs using processors from Intel-rival AMD. Given what we know about both companies' current line-ups, though, we are doubtful that iMacs or Mac Pros powered by AMD processors will be released anytime soon.

Apple CEO Steve Jobs said of the company's recent record breaking quarter that it had "amazing new products still to come this year." In addition to the Mac Pro, other products that have been seemingly ignored for updates include the MacBook Air, 30" Cinema Display, and Xserve, so perhaps desktop fans will get something before the year is out after all.