One of the favourites yeah, as one of the best teams in Europe. But as always so much plays a part, there are so many variables - form and tiredness at latter stages of the season, injuries, and not at all inconsequential is the luck factor in a knockout tournament.
It's too early to say really who will win it, but of course before a ball is kicked Barca will be a strong favourite. One thing though is that the longer Barca go without making a final the more of a psychological barrier it becomes (it has been ten years now and players and coaches are different but it can still hang over a club's head). Getting into last season's final (when it was well within grasp) would have stood the club in better stead for this season, even had they lost to PSG. I think that anyway.
Hopefully Barcelona can win it this season, though.