@the sad biker: see this page for all formatting codes available in the main site.
You can also use this really basic editor as draft editor... or the post interface of this forum (but all generated code won't work in the main site)

@antp: will it be a BBCode editor or something like tinyMCE, for the NextGen? I used this latter on several sites, it's really a good tool, easy to integrate and to personalize.