Marvel has a lot hanging on their box office this year. With RDJ getting too expensive to sustain further solo Iron Man films (phew), they need to be able to create new possible mini franchises like Guardians Of The Galaxy and prove that the other Avengers can maintain profitable film series as well and not end up as one offs if at all possible. Thor: The Dark World proved to be a successful follow up with critics liking it less, while still for the most part liking it, while the general audience liked it more. It slipped into last place for the top ten grossing films of 2013 bookended by IM3 in the top spot.
It's all on Cap now. The studio is optimistic having already signed The Winter Soldier's directors on for the third film and hiring screenwriters for a third Thor outing. Some others in the know have had high praise of what they've seen of the film as well. Ed Brubaker, creator of the Winter Soldier and one of the best writers to ever work on Captain America, has had nothing but praise for it saying he was "blown away" by the script a few months back.
I'm hopeful audiences will continue to embrace the MCU's take on these characters (Falcon aaaaaand Batroc?! Boom!) and are ready for a bit of cloak & dagger mixed in with their big screen comic book heroes. I for one can not wait.