The Office apps that come with the Surface are the real deal. It's the Home and Student version according to the web site.
It's Office RT, whatever that means. I tried to follow the link to the description http://office.microsoft.com/en-us/home-and-student/office-ho... - but on my Linux/Firefox combination, it shows nothing. Perhaps it's a silverlight thing, but the HTML is so messed up that I wasn't able to see if it was.
Way to go Microsoft!
(For all I know, it might still be the best available word processor for tablets; I have never used Apple's "Pages"; but previous versions were ... lacking)