Please view the official announcement where you will find links to the download, the updated Reference Documentation, and more: http://www.springsource.org/node/811
Also, note that we have launched a new Spring Extensions project for hosting any Spring Integration Adapters beyond those in the main distribution. We are intentionally keeping the main distribution limited to a small set of adapters that are either universally applicable or closely related to underlying Spring Framework functionality. The FTP Channel Adapters have been moved to the extensions project. You can find more information at the home page: http://www.springsource.org/extensions/se-sia
Thanks to everyone who has provided feedback here in the forums and via JIRA! Please download RC1 and continue to provide feedback as we move yet closer to the 1.0 Final release.