I just googled looking to do the same thing you are – move the site to root now that it is ready. Anyway, found http://wordpress.org/support/topic/24378 which said:
1. Go to admin panel > Options > General
2. Change the two URI adresses
3. Do not open your blog in a browser – yet
4. Open your FTP client (or other sie admin tool) and move the WP files
5. Now you can open and admire your blog
and if you skipped 1 and 2, follow instructions here: tamba2.org.uk/wordpress/site-url/.
Good luck!
