That's 3 out of 3 El Clásicos wins for Barcelona this season, with another one (League game) underway. Both teams will meet again two weeks from now in Barcelona. I don't expect the result will be any different, unless Barcelona has a safe points advantage over Real and gets overly relaxed.
That was the 32nd Copa del Rey win for Barcelona, who are number one in the ranking of the most cup wins, with Athletic Bilbao being 2nd (with 24 wins).
Barcelona are well set to win the league and they are a favourite to win the Champions League. If they were to achieve that, that could be one of the best, if not the best, seasons in the club's history. I don't think they ever won that many trophies in one season before.