Star Wars Celebration will probably bring in some crowds. How could you be right across the street and not visit SWGE? The end of the summer AP blockout will have a big effect on the crowds. Check the AP Blockout Calendar on the DLR website to see when the lower APs (Deluxe, SoCal, SoCal Select) are allowed back into each park. The week before and the week following any blockout is usually pretty busy as local APs hit the parks. Also, sometime around the third week of August, DLR usually goes back to the non-peak/low season schedule (i.e. shorter hours, less staffing, fewer rides running/more refurbs, less entertainment, F! and fireworks on weekends only, etc.). This can make the crowds feel heavier because there is less going on to spread out the crowds. There are no more guaranteed "slow" times in the parks -- only less busy times, but you have to take into account the reasons why those times are less busy. Also know that by the end of August, HM will be down for the installation of the Halloween overlay. So if that ride is important to you, try to visit before the third week of August.