Office 2013 has hit the RTM milestone. I've read that MSDN and volume license customers should be able to get their hands on the product sometime between mid-November and early December. Retail availability looks like it will be in early 2013. I would expect that Windows Surface RT should ship with an RTM versioned product! For the full details, check out the Office team blog.

http://blogs.office.com/b/office-news/archive/2012/10/11/office-reaches-rtm.aspx