This response is not only for Yale SOM, but for most top bschools. If you don't have any outstanding reason for why your undergraduate gpa is so low, then it will be a problem. If you've been working for a while, GPA will matter less, but will still be taken into account. Taking some college classes and doing well in them, and getting a high GMAT score will likely help. However, only to a degree.
Keep in mind, things like US News rankings and school profiles matter...a lot. The average GPA of incoming students are reflected in magazines publications and rankings. Therefore, schools just don't want to take a large number of people with lower GPAs because it will drag down their average, even if applicants have compelling reasons for poor UG performance or were simply immature in college. Like, nink mentioned, hope for the best but know that schools do care about GPA.