When using a list inside a content editable div, Shift Return adds a new bullet point (as would pressing RETURN alone) but should only insert a <BR> and add a new line without a bullet point dot.
Shift-Return creates a new list item in Tiger TextEdit too, so I don't think that's a problem (or something that should change). However, Option-Return and Option-Enter do insert a newline in the current list item in TextEdit but not in WebKit, so that may be a bug.
I think it should. SHIFT+Return for contenteditable should put a <br> in. Making a new list bullet is the wrong thing to do. I'm not sure if we've implemented Shift+Return acting as a line break rather than a paragraph break everywhere though.
I view this as a bug.
See also bug 16973.
*** Bug 21430 has been marked as a duplicate of this bug. ***