Regardless whether you love or hate Dart, I think it is a good move from Google to make Dart Editor available as early as possible. The editor is based on Eclipse (evidenced from the look-and-feel), the download is only around 36 MB. It requires Java, which is usually available in modern desktop systems. In a typical scenario, downloading and running Dart Editor with one of the sample applications just take few minutes.
While it is being worked on, Dart Editor already enjoys the standard expected features from an IDE such as project handling, class outline, and code editor with syntax highlighting and code folding. Autocomplete in the editor also works, which is joyful. It does even understand DOM and thus can autocomplete the elements and the associated properties. Don’t be surprised if more advanced features such as better syntax highlighting and integrated debugging will appear in the next iteration of Dart Editor.
Now the challenge is, where can I buy some spare time?