In the immediate term, I've been making do with this 'super ghetto submit preview':

1. Wrap your submission text with [html]...[/html] tags (I'm using square brackets instead of angle brackets here for reasons).
2. Save it as an .html file and open it in the browser.
3. That will give you a rough idea of how your submission will look, and you can double check all your links work and point to the right places.
4. [Optional]: You can put [p][/p] in the blank lines to preserve the paragraph structure, but you'll probably want to remove them again when you submit.
5. Then strip the [html] tags again, paste and submit...

Happy posting :D