The fact the standard bookmarklet takes you to the discussion for an already submitted article when you click "submit" is not at all obvious from the interface. There should really be some way to find out whether an article has already been submitted without any more than one or two clicks and without having to submit it yourself in the process.
What if I just want to see if it's on news.ycombinator to read any relevant discussion, but don't want to submit it myself?