Hope is perfecting a new 10-speed cassette designed for the SRAM XD freehub, and is nearing the final prototype phase of the project. Cassettes should be available in 10-40 and 10-44 tooth varieties.
The smallest seven cogs are made from steel, while the upper three cogs are 7075 aluminum with a hard ano coating. Aside from the weight savings on the big rings, doing it this way allows you to use the steel cogs as a 7-speed DH cassette when the larger aluminum cogs inevitably wear out on your trail/enduro bike. The jumps between the smaller gears are similar to SRAM's X0DH group, ensuring you hit the right gear faster.
2015 Sea Otter Classic Pit Bits