ipsi:menabassily: The update is only 20 MB and doesn't have anything to do with being rooted or not, and you don't really need Kies at all. Just go to the settings menu -> about device- > software update.
In which case my device is a bit buggered, because I've tried the update three times now, and it's failed each time. I'm attempting to update via Kies, but it thinks I'm already on the latest version. Suggestions?
EDIT: Actually, made a new thread for my issue: http://www.geekzone.co.nz/forums.asp?forumid=97&topicid=107865
Let me tell you a fact here, once you update your phone, it will be unrooted anyway, so try unrooting it to get the update, if this didn't work, try factory reset (after backup).