Greg; yes have been looking at integrating the existing SMF forums into a CMS - there have been various possibilities but when investigated nothing has been really robust enough to pursue - e.g. they've only been partially functional, no longer supported, etc. Part of the problem has been the SMF licence agreement; there was a proper SMF / Joomla bridge but because the chosen licenses became incompatible it was shelved.
Of course sticking with SMF isn't set in stone and recently we've been evaluating alternative forum software which may open the way to better CMS integration.
Sorry if this is obvious, but would it need integrating? Skin it so that it appears the same and run them side by side? I understand that runs the risk of the forum (or the content) looking like something tagged on.
I think it would really - can you imagine needing one login/password for the forum, then another if you wanted to comment on an article, photo or vote on a problem database grade, etc? It'd be a right pain.