Sounds a lot like the much-hyped Orbitz. Backed by the major airlines, it promises discounts up to 40% (But like NW cybersavers, no FF miles).

Unlike Priceline, you can see a price before booking.

I tried a fare I already booked for December and discovered Hotwire could have saved me money: $1/ticket.

I eagerly await the route where I save 40%.
http://www.hotwire.com