After searching around the internet, this is the list of 29er rims, 35mm and wider, that I can find. Did I miss any?
Velocity P35 rim: 32 or 36h, 35mm, 595g, double wall, disc only
Salsa Gordo rim: 32 or 36h, 35mm, 700g, double wall, disc only (discontinued?)
Kris Holm XC rim: 36h, 38mm, 795g, double wall, disc or rim
Kris Holm Nimbus Dominator rim: 36h, 42mm, 903g, double wall, disc only
Velocity Snow Cat rim: 32h, 44.5mm, xxxg, single wall, drilled holes, disc only
Kris Holm Freeride rim: 36h, 47mm, xxxg, double wall, drilled holes, disc or rim
Surly Rabbit Hole rim: 32/64h, 50mm, 699g, single wall, drilled holes, disc only (not yet released)
Speedway UMA rim: 3xh, 50mm, xxxg, double wall, disc only (discontinued?)
All in all, it's a pretty short list of wide rims for 29ers. There are no remaining double wall rims wider than 42mm and no 32h rims without drilled holes wider than 35mm.
My hope is that the Surly Knard will add to mounting pressure for manufacturers to put out more wide 29er rims in a variety of styles and configurations. I've heard rumors that Velocity is going to be putting out a double-walled, ~45mm rim, so perhaps there is hope. And Jeff Jones keeps hinting that he is going to be selling 50mm 29er rims.
Velocity P35 rim: 32 or 36h, 35mm, 595g, double wall, disc only
Salsa Gordo rim: 32 or 36h, 35mm, 700g, double wall, disc only (discontinued?)
Kris Holm XC rim: 36h, 38mm, 795g, double wall, disc or rim
Kris Holm Nimbus Dominator rim: 36h, 42mm, 903g, double wall, disc only
Velocity Snow Cat rim: 32h, 44.5mm, xxxg, single wall, drilled holes, disc only
Kris Holm Freeride rim: 36h, 47mm, xxxg, double wall, drilled holes, disc or rim
Surly Rabbit Hole rim: 32/64h, 50mm, 699g, single wall, drilled holes, disc only (not yet released)
Speedway UMA rim: 3xh, 50mm, xxxg, double wall, disc only (discontinued?)
All in all, it's a pretty short list of wide rims for 29ers. There are no remaining double wall rims wider than 42mm and no 32h rims without drilled holes wider than 35mm.
My hope is that the Surly Knard will add to mounting pressure for manufacturers to put out more wide 29er rims in a variety of styles and configurations. I've heard rumors that Velocity is going to be putting out a double-walled, ~45mm rim, so perhaps there is hope. And Jeff Jones keeps hinting that he is going to be selling 50mm 29er rims.