Truvativ's Hammerschmidt prototype will be available for test at Eurobike (September 4th-7th). The two-speed crank allows the rider to run a shorter chain and should, in theory, make shifting near perfect. Truvativ even speculate their new system could be the downfall of the front mech.
The crankset will offer plenty of ground clearance and will go down well with bike designers, offering plenty of choice when placing pivot and swingarm locations.
Two versions, an all mountain and a freeride version are likely to launch in 2009. Concerns are appearing over the weight, with some forums speculating that the weight of the All mountain model sits over 170 grams heavier than the majority of current systems.
For more info, see here.