You are right,Barcelona have changed it shape under Xavi,the club and the players are doing so well that one begins to imagine them win the Lalliga and probably do very well in the champions league this season.Last season,it was Madrid that won the Champions league and the Lalliga,perhaps the tittle might still be at Spain,maybe Barcelona will win it this time around.
Nevertheless,I'm not too sure because we have other good teams like Mancity,Bayern and PSG,that we can call strong tittle contenders for the Champions league trophy.
Real madrid and Barcelona are both rivals for both the laliga title and they might also compete for the champions league title. Concerning barça Winning the champions league, I don't think they would win it this season, more chances from other clubs. The only competend team that are under probability to be crowned UEFEA champions this season is Real Madrid and Manchester City. We have strong clubs this season and as things stands, no time would want to be sent off at early stage, they all wants to qualify for the next round. Today is the opening leg in the champions league, I would be expecting big teams to win the lesser clubs, as a matter of fact, there's no small club in the champions league. For a club to qualify for UEFEA, that club is not considered a small club.