I was just crusing Dirty Linen's events & festival site & saw that Mystic is list with a line up. I don't know if it's partical or full, there's still no listing of performers updated at their site
Here's what they've got so far:

June 11 - 14

Danny Spooner
Nanne Kalma & the Hudson Crew (Nanne & Ankie + 4)
Louis Killen
Talitha MacKenzie with Serre L'Ecoute
The Clancy Legacy (Aoife Clancy, Donal Clancy, Robbie O'Connell) Dick Holdstock & Allan MacLeod
Bob Walser
Stuart Frank & Mary Malloy
Cliff Haslam

Barry