Well I was never a huge fan of prebuilt JS Libraries, especially when they are loaded from a different server however i find googles implementation of this AJAX API loader interesting. Looks like they want to be hosting the internet as well.

I guess this may help them when it comes to searching AJAX based webpages if they are hosting the JS libraries used.
The AJAX Libraries API is a content distribution network and loading architecture for the most popular, open source JavaScript libraries. By using the Google AJAX API Loader's google.load() method, your application has high speed, globaly available access to a growing list of the most popular, open source JavaScript libraries including:
http://code.google.com/apis/ajaxlibs/