I was there 2 weeks ago and using fastpass was a must with the crowds. Here's an example of how we used them on 6/21 (times are approximate):
Arrived MK 9:00
Went to Space Mt - got fastpass for 10:10
Rode Peter Pan - short wait
Went to Cinderella Breakfast - 9:35 to 10:35
Went to Buzz - got fastpass for 11:30
Rode Space Mountain - used fastpass - standby was about 40 or 50 min
Did Carousel of Progress - no wait
Did TTA - no wait
Rode Buzz - used fastpass
Walked to Big Thunder - got fastpass for 12:50 at about 12:10; standby was showing 40 min.
Did Hall of Presidents (12:30 show)
Rode Big Thunder - used fastpass
Got fastpass for Jungle Cruise - for about 2:00
Did Tiki Birds - next show
Did Country Bears - next show
Rode Jungle Cruise - used fastpass
Left around 2:30 to go back to hotel for a rest. We had done other attractions at MK on Monday evening (Haunted Mansion, Splash Mt, Small World, Philharmagic, Spectromagic, Wishes).
The key is to get fastpasses and do short lines in between.