Surly have just finished putting together their first-ever touring tyre! It’s called the ExtraTerrestrial and it’s FAT!
They’ve incorporated a heap of protection in the rubber too. There’s kevlar between the treads, a nylon breaker in the sidewall for cut protection, a pattern moulded into the sidewall to help prevent cut propagation and a file tread between the main tread blocks for additional puncture protection.
The ExtraTerrestrial’s tread is directional and quite similar to the Schwalbe Marathon Mondial. One advantage it has over the Schwalbe is smaller side knobs which should hook a bit better into dirt surfaces. The sheer width of the tyre provides a bigger footprint and more grip too. You can run the ExtraTerrestrial tubeless, with rim widths ranging from 24-50mm. Given the smooth-ish ridge along the middle, it should be relatively fast on the road.
The tyre is available in one size only: 26×2.5″ (62mm), optimised for the Surly Troll. It will be available in early-2016 for US $60.