That's nowhere near elegant!
My hate for BBcode burns with the fierce intensity of a million suns. The great thing about markdown, which I've tried to copy as faithfully as I can, is that it looks good even when it ISN'T parsed. You can publish a text written in markdown as a text-only document, and nobody will even notice. Similarly, if you write text in WakabaMark on a board that doesn't support it, it won't make you look like a retard, like BBcode does.