Who's Building It: Orbital Sciences Corporation
Key Features: Commercial cargo vehicle, developed by successful space contractor company
Powerplant: Hydrazine thrusters, launched aboard Taurus II rocket
Capability: Low Earth orbit for Space Station resupply
Payload to Orbit: Payload mass of 2,000kg in 18 cubic meters of space
System It Replaces: Space shuttle cargo transfer to ISS
Due Date: Demonstration flight 2010, in service until 2016

Cygnus is even less glamorous than SpaceX's Dragon, since it's essentially an uncrewed rocket-truck. It's designed to haul cargo up to the ISS--it's a simple "space tug". It's part of the same NASA contract as the Dragon, and will be built as a commercial vehicle.