When the CMS launches a dialog box - for example when renaming an asset - the first field on the dialog should have the focus, and the text within that field (if applicable) should be pre-selected to make changing/entering a value as streamlined as possible. Hitting return should then execute a click on the default button on the dialog.
For an example of how this should work, on Windows hit winkey+r. The box that opens up has your previous command pre-selected. You can type in a new one and hit enter to run, without ever having to move the mouse or click.