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
3666420901741926662
true
Search Help Center
false
true
true
true
false
false
false
false