Yep, Johnny has some amazing chops - on the acoustic or the electric! That Guild sure is a sweet-sounding guitar, too...kinda Taylor-ish in its' brightness and clarity.
He may have been hybrid picking some of it, but a lot of it looked/sounded like banjo rolls and cross-picking. Bluegrass is some tough stuff to play! I've just started messing with some of it -
here's a good site with some helpful tips and lessons for bluegrass. Another one
here.