Since theres no "meta" forum, I'll put this here.
It takes a lot of time and painstaking effort to write a decent technical question, and on two occasions now I have had to redo it because I clicked 'Preview', and then instinctively clicked 'Cancel' to exit the preview. Obviously, I should have clicked 'Edit' to get back, but it's intuitive (and deadly) to take it's meaning as "cancel out of preview" and click it without thinking. Also, it's the farthest right button so it sticks out as "probably the button to 'get on with it'". Then it cancels your message and sends you back to the forums.
There really is no reason to even have a cancel button, who would ever write a question, go to preview it and then think "never mind, I want to go back to the main forum page, how could I do that? I know, I'll click cancel out of my message". If people want to cancel a question they will close their browser tab or click the "Forums" button at the top to go back to the Forums, if that's what they want to do. I just don't see any use case for the cancel button at all and only it's potential as a trap.
Don't mean to complain but since it's bit me twice now I thought I'd put my 2 cents out there, for whatever it's worth ($.02?)