Basically there are now 2 rope drops for MK. One to get on Main and one to head to wherever you're going in the park. If you have a firm destination in mind and you want to be at the front of the pack, I'd get there at 7:30 as well. You'll be let in somewhere around quarter til 8, ten til 8, and Main Street is open, you then go up toward the castle and pick your route and stand at the rope. So, 2 herds to get the jump on.
Last time I tried that I went to Peter Pan... lined up and the ride broke down and nobody came out to tell those in the line inside the building. Sooo... that didn't work out to well. lol Just remember to expect the unexpected.