I go around this time every single year. My favorite time to go. Park hour are longer except for on the 27th (Of this year) for grad night. But currently DL closes at 9 and DCA closes at 6pm. Every other night that week closes at 11 or 12. So that is always a bonus. But the crowd level is always decent. Not slow, but not crazy busy either. The major rides like Indiana Jones, Splash or space Mountain might have 45 minute-hr wait, but others may only have a 15-20. Just make good use of those fast passes and you will be totally comfortable.
I too am going around these dates, and I do have to agree that Fantasmic will draw in more people as it has been down for awhile, and there is a possibility of soft openings for the World of Color which might bring in even more people to view. I honestly cant say how these 2 are going to effect park crowd levels, but I do expect it to be a tad busier then normal. So definitely Fast Pass it.