We've found that there is little effect on the crowds in the morning at DL so you'll be able to get a lot done. As they start arriving during the day the grads have parkhopper tickets so they tend to be in DL during the afternoon and evening. They are most noticeable in Tomorrowland and at the thrill rides (e.g. Indy, Splash, Matterhorn, Big Thunder) so I would do those rides in the morning.
There probably won't be too many grads in DCA in the afternoon and earlyevening because they will have access to the rides in DCA after the park closes to the public.
For the non-grad night attendees, DCA will have its regular closing time with a WOC show and afterwards there will be an uptick in the DL crowds where many will end the evening.
