The Leader was Jordi Pujol of CDC. Currently, Josep Antoni Duran i Lleida of UDC is the leader.

Actually I was wrong: the leader of CiU is now Artur Mas of CiU, but there was a considerable amount of jockeying between him and Duran i Lleida to succeed Jordi Pujol. Unió is the junior partnet in the coalition (I don't know based on what, given that CDC and UDC have never contested an election separately AFAIK), but Duran i Lleida was widely perceived as more of a heavyweight than Mas and, after over 20 years of playing second fiddle to Pujol, Duran and UDC generally probably felt it was their turn to take the lead for a while. It did not happen, but without Pujol at the helm and having lost the Catalan government, Duran is a more towering figure and enjoys national exposure since he is the one leading CiU's parliamentary group in Madrid while Mas leads the opposition to Maragall in Barcelona. Duran and Mas will often contradict each other in public when reacting to national issues.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman