Uni doesn't own the production rights to the Hulk. Marvel does. What Universal has are the distribution rights, which is why they distributed 'The Incredible Hulk' even though it was produced by Marvel Studios. Disney has to determine whether or not they want to share those distribution revenues or pay off Universal for them. Unless they feel they can make a killing with a solo Hulk movie, which hasn't proven to be the case, I don't seem them making any deal any time soon.
So, Marvel can make a Hulk movie any time it wants. It just has to use Uni to distribute the film instead of Disney.