Xorg 6.9 is now in the DragonFly binary pkgsrc archive, as noted recently by Joerg Sonnenberger.
Check the Xorg link above if you don’t know the difference between Xorg 6.9 and 7.0. The new features list mention DragonFly BSD support, along with some odd things like support of mice with more than 12 buttons.
Who the hell has a mouse with more than twelve buttons?
If you got one of those mices with “tilting” scrollwheel you got at least 7, only 5 to go :-)