Links with OnClick events embedded - good or bad for SEO?

I guess there's a threat of someone linking with the whole OnClick code and causing some dupe URL issues.

Any thoughts???

Indifferent. Since the onclick event is a Javascript issue it's to all intents and purposes ignored by the search engines. What counts is whether or not you link appears in the href attribute, and whether or not the link is nofollowed.

I'm not quite sure what you're referring to by the "duplicate content issues" resulting from the use of onclick.