When editing a question or an answer on StackOverflow, it would be great if, when you are on a line that starts with n ≥ 4 spaces and press Enter, the newly created line would automatically begin with n spaces, and the caret would be at the end of the line.
Update
After having struggled with the Shift+Return approach a few weeks, I have to admit that it is a horrible substitute for real AutoIndent. Two new lines are inserted per Shift+Return, and the indent of the new line is not n spaces (n being the number of spaces of the previous line), but the constant 4. Also, there is an annoying default text; although selected, it is annoying. So I revive this old feature request: I want AutoIndent!