I just did this. My thinking was pretty simple. My 3610 fleet is not going to change much so I am not worried about new ap registration. I was worried about the minor pain of changing my v9 controller name from controller to something else. In the future I may use a CNAME or something to point at controller to be more flexible and teach my techs a more specific name like controller1, controler2, etc.
I went ahead and set up option 78 to point at my v10 controller (named controller10 of course!). Everything is working great. My 3935 and 3965 ap's find the controller very quickly.
I hope this helps,
Jeff