We have released updates to the Gravity Forms MailChimp, Campaign Monitor and FreshBooks Add-Ons. These updates are to insure compatibility with the upcoming final release of WordPress 3.0.
You can get complete details here:
Developers who have access to the Add-Ons can upgrade via automatic upgrade or manually download the add-ons via the add-ons page.
If you have already installed WordPress 3.0 beta or release candidate you will need to manually upgrade as the automatic upgrade code in the old version of the Add-Ons do not work in the 3.0 release which is what this release corrects.