AppleInsider recaps many of the circulating rumors which expect both iPod and Mac notebook updates in the coming months. Some rumors have pegged September 9th as the possible day for at least some of the updates.
The iPod Nano and iPod touch are expected to see revisions, and long standing MacBook and MacBook Pro rumors point to revised case designs (MacBook, MacBook Pro) that adopt an aluminum/tapered look.
Newly reported, however, are expectations that the Apple iMac will see a refresh prior to the holiday season:
Separately, Apple is also planning to refresh its line of 20- and 24-inch iMac seasons ahead of the holidays. People familiar with these plans have described the refresh to consist of 'speed bumps' rather than major internal or external changes. Based on the roadmap presented to AppleInsider, these systems would debut later this fall following the release of the new MacBooks, making their way to market with little fanfare.
An iMac update would be contrary to expectations as the iMac is the most recently updated Mac. The iMac was updated in April of this year and introduced early Montevina-like technology. As a result, there would be only marginal improvements if it were updated to the most recently released Penryn/Montevina chipsets.