Adding a link is UNBELIEVABLY slow using the existing method. It takes about 6 seconds to pop-up a new window on Firefox or IE, about 4 seconds in Opera.

Please don't subject us to this kind of delays just for a link. There's no need to fetch a new page from the server just to add a link. Use AJAX if available. It will speed things up incredibly. Please see http://stackoverflow.com or the wmd page (http://wmd-editor.com/examples/splitscreen) for examples.