Monsters inc sequel. Will it really be as good as the first?

On June 20th, Monster University (the sequel to the 2001 Disney/Pixar movie Monsters inc) trailers have been appearing from different sources all over the internet. The movie appears to have the old gang back including James P Sullivan (Johnny Goodman) and Mike Wazowski (Billy Crystal). The only difference in this movie is that it's set in... college, hence the name Monsters University.
Everything seems okay from the trailers I have seen so far, but the biggest question remains: will it be as good as the first?
The sequels are always the hardest to receive good reviews from viewers due to people not thinking that it's not as good as the original. The same problem was with Pixar's Cars 2. It was just an okay movie; not the best or worst but it just made it by the skin of its teeth.
One other problem would be if you would have to watch the previous film to understand the characters (even though it's set ten years before Monsters inc). Pixar had made a great move when they made the film where you didn't have to watch the previous films for Toy Story 3 to understand the third one so I take my hat off to them, but will they do this in Monster University?
Here is a trailer for the 2013 movie...