Dreamliner is Boeing's marketing name for the new 7E7, a new 200-280 seat long hauler (depending on which model you pick).
It's reported that Emirates will be the airline concerned.
Although it might seem to some that EK is buying everything in sight, there is considerable sense for EK to make sure it has the most efficient, medium sized long hauler, as this is effectively its "lead in" aircraft, allowing it to starts routes to relatively peripheral airports, as its 330 has done to BHX and (soon) GLA and (hopefully!) Dublin, then building them up to 777s and larger types in due course. Good luck to them.