My dad actually suggested something about this on our vacation...that those using tickets for the first time (so those needing photos/signatures) should have their own lines so that those who already have everything all set can get in faster. but, as darkbeer1 said, that requires that people read the signage. Even if you split the turnstiles in 1/2 and said the 1/2 to the right are for first use, 1/2 to the left are for those who already have signatures and photos, you'll still get plenty of people who don't read the signs at all. I have to admit
disneyland did a good job with the entry lines and adequately staffing the turnstilea. Even when we were so far back in line that we were closer to dca than dl, it didn't take more than 20 mins or so to get from there through the turnstiles.