My understanding is TSA Pre is going to 2-3 X-ray belts, instead of 1-2.

This weekend, the line for Pre was nothing, but the SkyPriority line at CP4 was insane. A big part of that is because the ID checker would alternate with the regular passenger line.Now there will be more room for Pre (which will help during the weekday morning rush) and a dedicated ID checked for Sky Priority.

Should be a big improvement to the security experience for elite passengers.

PS: It's really amazing how much faster Pre is than Sky Priority. My wife was traveling with me on Saturday morning and I whipped through pre in about 2 minutes. She spent almost 15 minutes waiting in the Sky Priority line. Hope this change improves that.