There is a new terminal at the Barcelona Airport so I am searching information about it in case I need to go there soon … Here I write about what I find … In fact I am looking at the url http://www.aena.es/csee/Satellite?cid=1232555236520&pagename=PlanBarcelona&SiteName=PlanBarcelona&c=Page&Language=EN_GB
The old terminal now is called T2 and the new terminal is called T1. If you reach the airport by train then you have a shuttle bus service that brings you to T1. It should not take longer than 10 minutes, it seems. The metro line L9 is under construction and it will reach too T1. In a video on that URL you can see how to reach the terminal by car. The buses wait the trains. There will be also shuttle services between T1 and T2 each 5 or 6 minutes.

Star Alliance are the first to move to new terminal. Then in September One World and later Sky Team.
There are different levels. Level 3 is for departures and level 0 is for arrivals. There is one place called LA PLAZA.

On June 17th I already see companies like SPANAIR, LUFTHANSA, AIR COMET, etc operating on T1.