Every school has improved absolutely, and because of this, few schools have improved in relation to one another to any significant degree. In fact, I am willing to bet that several of the changes in rank from year-to-year are not due to university policy as much as it deals with changes in the formula US News uses.
So I have a more vague answer to your question, when looking at the schools themselves, see how their funding stacks up, and when interviewing, check out the amount of construction that is going on. These are the schools that are most likely to "improve" rapidly.