I suspect that Joyful Noise might be done. His remaining dealers seem to have nothing but old stock. Curt made extraordinary instruments but at the end of the day, I suspect that there is a limited market for $1500 snare drums.
I am happy to hear GMS is still going . Their lacquer finishes are superb and their drums sound fantastic . One of my local shops was a GMS dealer and they got the ocassional kit in and they all sounded great . GMS is my second favourite Boutique builder after Noble and Cooley .
Baltimore Drum Company is still around. You can read the history of the company on BDC's website: http://midatlanticdrum.com/baltimore-drum.html. The relationship with the investor who was brought in soured and it took some time for Keith Larsen to right the ship.
According to the Joyful Noise Facebook page they've changed phone numbers, there appears to be not much else activity lately though.
Perhaps someone here who is in the authorized dealer network can update us with more accurate information on future product availability?