Here's a few:
Gary Kramer:
- F-1: A 36 Fret "ergonomic" 7-string

Todd Kehn (TK Instruments):
- Hollow 7

- He's technically not making 7-string guitars any more, but he has said that if he gets enough interest, he might.
Halo:
- BH-7

- Pretty much all models can be semi-custom ordered in 6, 7 or 8 string version
Hancock Archtop Guitars:
Teuffel:
Guerilla Guitars:
I think
Manne makes a 7-string too, but I can't hit their site right now.
I have a whole bunch of vendors bookmarked, I'll crawl through the list and see if I can find more. These are just the ones that I remember off the top of my head that make 7-string Guitars.
* ElRay Puts nose back to grind stone after much needed diversion
Ray