It really depends on what your future goals are, and how much the title means to you. At this time, they are not requiring a doctorate, but they likely will in the future for new graduates. You do not need a doctorate to practice independently, in those states that allow independent practice, you can do that with an MSN. If you are already in school for a DPN, and have the means to complete the program, I would stick with it. As previously mentioned, it will allow you more options, such as teaching in MSN programs, or being a director in some companies. You will not be able to call yourself Dr. Lastname in practice, but it will look nice on your resume, business cards, and lab coat. Plus, if you ever teach, you can make your students call you doctor.