The Walt Disney World resort has abridged the construction impact of the Skyliner from their original announcement:

Quote Originally Posted by Walt Disney World Transportation

FriendShip boat service to Epcot will be suspended at 9:30 PM each night until late December 2018. This service connects Epcot with the following Disney Resort hotels:

Disney’s BoardWalk Inn
Disney’s BoardWalk Villas
Disney’s Beach Club Resort
Disney’s Beach Club Villas
Disney’s Yacht Club Resort
Walt Disney World Swan Hotel
Walt Disney World Dolphin Hotel

Bus transportation to Epcot and the pedestrian walkway across the bridge will remain available during this downtime.

As part of a presentation at IAAPA 2018, Disney has set an official opening date for the Skyliner:

Quote Originally Posted by Disney Parks & Resorts

Bob Chapek, Chairman of Disney Parks, Experiences and Consumer Products, announced that Disney Skyliner will be ready to begin transporting guests at the Walt Disney World Resort beginning Fall of 2019!

As recent Guests will have likely noticed the visible (and often sight line ruining) construction of the Disney Skyliner around the Walt Disney World resort, a new promotional video has been released:

Of note, the video confirms that there will be three separate lines:

Epcot <=> Disney's Riviera Resort <=> Disney's Caribbean Beach Resort
Disney's Hollywood Studios <=> Disney's Caribbean Beach Resort
Hour Glass Lake <=> Disney's Caribbean Beach Resort

Guests traveling from the Hour Glass Lake station (Art of Animation & Pop Century) will need to change at the Caribbean Beach station to travel on to Epcot or Disney's Hollywood Studios with no "direct" line access to either park.

Although the video remains devoid of a grand opening date, related internal documents are pointing to a Mid-2019 opening date for the Skyliner system.

As part of the continued construction project for the Epcot Skyliner station, FriendSHIP boat service to Epcot's International Gateway has been internally announced to be suspended November 28th through December 18th, 2018.