With the AJAX API loader, do I have to change my code if I'm already using AJAX Search, AJAX Feed and/or Maps?

No. If you prefer to leave your working code alone, that's fine. We'll continue to update and maintain the G* naming scheme alongside the google.* naming scheme. For more information on the AJAX API loader, please see the documentation.
Google apps
Main menu
18271134955532692748
true
Search Help Center
true
true
true
false
false