The memory modules were reportedly able to deliver these speeds when tested on several P55-based systems, including the Gigabyte GA-P55A-UD4P motherboard. There's no word on pricing yet, but we wouldn't count on them being cheap as Kingston says that the new memory kit is targeted at "enthusiasts, gamers, and benchmarkers looking to scale new memory heights." They are also backing them with a lifetime warranty and free 24/7 technical support.
A look at Intel's memory qualification chart (PDF) shows that Kingston's memory is just ahead of Corsair's CMGTX1, which runs at 2,333MHz with identical latencies and voltages. These are priced at a hefty $200 per 2GB module, so you can probably expect to pay a similar premium Kingston's offering.