There's a service like this out there, although the list of participating artists is fairly small:
TourGigs // Concert Films
The key seems to be finding a listener base that will keep coming back for more of the same artist...so Jam Bands are perfect!
We recently used this service to watch Jason Isbell live from the Ryman Auditorium and it was excellent- HD Video with a very solid audio mix. Was really fun to be able to "go to a show" with my wife without having to get a sitter!