David99,
The past 7 years have seen 'Bluegrass' move far from its centrist roots and adventure into all sorts of genre.
'String Cheese Incident' is probably the most bastard child of all with electric mandolin complete with distortion pedal. They really are great though.
Guitar driven bluegrass/folk, Tony Rice is always on.
David Grisman with his 'DAWG' music is quite progressive.
Alison Krauss with Union Station is quite solid.
Outside the lines look for Jerry Douglas, Sam Bush, Edgar Meyer and Bela Fleck. Together or solo these guys have redefined the genre altogether.
'Restless on the Farm'-Jerry Douglas
'Howlin' at the Moon'-Sam Bush
'Skip, Hop and Wobble'-Meyer, Barenburg, Fleck?
'Uncommon Ritual'-Meyer, Fleck and Marshall
These would make a good primer.