Saw the same message. Have installed Eclipse 3.7 and also a linked GWT SDK[GWT - 2.4.0].
So I did the obvious thing, viz., Check for Updates. Eclipse reports "no updates available". What now? -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To post to this group, send email to google-web-toolkit@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.