Tip of the hat to Patrick Fergus on the MacEnterprise list:
Apple Knowledge Base article on managing iTunes 8.1 and later:
At the bottom are new keys added in iTunes 10:
Each of these take a boolean value.
Previously there was a single “disableCheckForUpdates” key that, when set to True, would disable both checking for updates to iTunes and checking for updates for iPhone/iPod/iPad devices. Now you can be more granular in your management.