Yes. You can pass the "lang" parameter when in the forums listing page:
http://host/jforum.page?module=forums&action=list&lang=xx_XX
where "xx_XX" is any of the values available in WEB-INF/config/languages
However, I'm not sure if this feature is working correctly - at least for the development version this is bugged (and already registered in the bug tracker).
Rafael
[originally posted on jforum.net by Rafael Steil]