Q. Which hotels offer the ESPN Direct Express Bus at no additional charge?
A. The Disney All-Star Sports Hotel, Disney’s All-Star Music Resort, and Disney’s Caribbean Beach Resort include the direct express bus service to and from the event each day. These shuttles are only available for team members who made their reservations through the VEX World Championships packages booked through Get Travel. Teams booking through Get Travel will get passes for this express bus service.
There are 5 Disney hotels that offer free 
transportation to ESPN even if you don’t book through Get.
Disney told me Pop Century Resort is the closest hotel to ESPN and is the only one with a direct (no stops at other hotels) bus.
From Disney’s ESPN web site:
Bus transportation to ESPN Wide World of Sports® is available from Disney’s All-Star Resorts [Music, Movies, & Sports], Disney’s Caribbean Beach Resort and Disney’s Pop Century Resort on a limited schedule:
Thursday - Monday 5:00 p.m. to 11:00 p.m.
These buses will also run when events are taking place at the Sports Complex based on the following schedule:
One (1) hour prior to Sports Complex opening until 11:00 p.m. or Sports Complex close, whichever is later
During the scheduled operating hours, buses from Disney’s All-Star Resorts, Disney’s Caribbean Beach Resort and Disney’s Pop Century Resort to ESPN Wide World of Sports® will arrive at the Sports Complex on the hour and ½ hour.
Glad this info was posted – just switched our reservation to the Pop Century Resort. Disney confirmed it’s the best choice if we’re going to ESPN & they still had great rates even this close to Worlds. With Disney’s free airport shuttle plus free transportation to ESPN - what a steal compared to Get Travel’s pricing! 