The new 3.0 version of Webform provides vastly improved APIs, integration with more modules, conditional field logic, e-mail templating, and more (see CHANGELOG.txt). The 2.x version is no longer supported and will not receive any further updates. All users should update to 3.x.

Please note that there are some caveats with upgrading from 2.x to 3.x:

• You cannot downgrade to 2.x once you have updated to 3.x. Make a database backup before upgrading.
• The Additional Processing and Validation code options have moved to a separate project. Webform PHP. Any such code from your 2.x webforms is preserved on upgrade and can be found in the {webform} table in the database, in the additional_validate and additional_submit columns. However this code is not executed in the 3.x version of the module unless Webform PHP is installed.
• Theming of emails has changed in 3.x and you will need to remove any custom theming (webform email templates in your theme's directory, webform email theme functions in template.php) you have done. If submitted values are missing from emails sent by webform then you probably have a 2.x template somewhere! You can recreate your custom e-mails through the built-in e-mail templating interface in 3.x or retheme them with the improved 3.x theming system according to the information in THEMING.txt. See also Customising the emails sent by webform.
• Some add-on modules do not yet (as of May 2011) support the 3.x version of Webform. If you're using a module that extends Webform, check with that project before upgrading.
• The Webform Block module is now built-in to Webform. It should not be installed at the same time as Webform 3.x.

All of your existing forms and submitted data will be migrated to the new version upon running update.php.