There's the Strawberry Park Bluegrass Festival on June 1-4 in Preston, CT: http://www.strawberrypark.net/bluegrass.htm with:
Rhonda Vincent (Sunday)
The Grascals (Saturday)
The Bluegrass Gospel Project (Sunday)
Mountain Heart (Thursday)
Tim O'Brien (Saturday)
Gibson Brothers (Friday)
Nothin' Fancy (Sunday)
Dale Ann Bradley (Friday)
Dry Branch Fire Squad (Saturday & Sunday)
The Kruger Brothers (Saturday)
Blue Highway (Saturday)
Cherryholmes (Friday)
April Verch (Friday & Saturday)
King Wilkie (Sunday)