We're happy to announce that the Dart Editor Plugin for Eclipse is ready for preview. There are still some rough edges and we don't have feature parity with the standalone Dart Editor but there's enough in place that interested folks may want to check it out.
Important note: on initial install, a secondary download of the dart SDK will occur. The download should only take a few seconds and will happen in the background with progress displayed in the status line. When it's done, you'll need to restart eclipse (again). (For the curious, this second restart is required to get the SDK properly recognized and is only a short-term work-around -- but hey it's an alpha!)
As always, your feedback is greatly appreciated. (And we're counting on it! :)) For general issues and feedback, feel free to chime in on issue 702, or open a new one on dartbug.com.