The decision seems to be the result of a more profitable revenue sharing agreement, indicating that Yahoo outbid Google, who is -- or was -- the default search provider. "I am pursuing this change because Canonical has negotiated a revenue sharing deal with Yahoo! and this revenue will help Canonical to provide developers and resources to continue the open development of Ubuntu and the Ubuntu Platform," Spencer said.
The switch will appear in the development version of Ubuntu "as soon as reasonably possible" and will be in Ubuntu 10.04, which is due in April. Whether changes will be made to existing stable releases is not known. Regardless, users will be able to easily swap back to Google or any other engine if preferred.