50 performers have been confirmed for this year's HSB festival, which takes place the weekend of 09/30-10/2/11::

Confirmed:
Ralph Stanley & the Clinch Mountain Boys
Southern Culture on the Skids
Alison Brown Quartet / The Low Anthem 
Conspiracy of Beards 
Greensky Bluegrass 
AllofaSudden
Blame Sally
Dry Branch Fire Squad 
Thurston Moore
Bill Kirchen 
The Belle Brigade
Jason Isbell & the 400 Unit 
Nell Robinson & Jim Nunally with their All-Star Band 
Those Darlins 
DeVotchKa 
David Bromberg Quartet
Ollabelle 
Justin Townes Earle
The Wronglers with Jimmie Dale Gilmour

Dr. John
Punch Brothers
Gomez
Dark Star Orchestra
Bela Fleck, Zakir Hussein & Edgar Meyer
The Civil Wars
Bob Mould
The Devil Makes Three
John Prine
Emmylou Harris
Gillian Welch
Ryan Bingham and the Dead Horses
Robert Plant
Fitz and the Tantrums
Robert Earl Keen
Abigail Washburn
The Jayhawks
Cass McCombs
The Del McCoury Band and the Preservation Hall Jazz Band
Patty Griffin
Old Crow Medicine Show
The Blind Boys of Alabama
Irma Thomas
Elbow
The Mekons
Earl Scruggs
The Flatlanders
Chris Isaak
Frank Fairfield
Buckethead

Uncomfirmed (but likely, according to Pollstar):
Merle Haggard
Reckless Kelly
Doc Watson

Sadly, no Hazel Dickens this year (RIP).