Is there going to be another avengers movie?

Well supposedly, because if you watch till after the credits there is another trailer which sees the the villian in captain America talking to someone who may be Loki suggesting another attack... only problem there is that red skull dies and at the end of captain america. in the avengers the enemy invaders are talking to another alien race called skrull. which invade in the comics

* Actually, Red Skull was not killed at the end of Captain America. He was, instead, transported, though we don't know where. So it is highly possible that Loki is talking to Red Skull at the end of the credits in The Avengers.