Apple released Mac OS X 10.6.4 Update iMac (Mid 2010) for its new iMac models and has introduced the Magic Trackpad and Multi-Touch Update.
Mac OS X v10.6.5 Update iMac Mid 2010 (http://support.apple.com/kb/DL1065) is recommended for all users of the new iMacs. This update contains all the applicable fixes from the Mac OS X 10.6.4 Update, plus the following specific fixes for iMac (Mid 2010):
° Resolves compatibility and performance-related graphics issues;
° Improves compatibility with large-format SDXC memory cards’
° Adds support for Magic Trackpad.
It requires Mac OS X 10.6.3 or higher and is a 452.62MB download.
The Magic Trackpad and Multi-Touch Update enables Magic Trackpad support on Intel-based Macs. It also adds inertial scrolling and three-finger drag gesture support to recent MacBook Pro and MacBook models. It requires Mac OS X 10.6.4.
Both updates can be obtained via the Software Updates Component of Mac OS X’s Systems Preferences app.