I'm a similar boat, a little further along. MPA '11, with a full-time city government job which followed from an MPA internship. I'm developing towards a small-town manager position, but there are still a couple more steps. At least in some parts of the country, MPA+internships isn't enough. This job posting from our municipal league shows some gaps we need to fill.
"Interim Town Manager, Exmore
SALARY: $55,000-$75,000 DOQ/DOE (+) benefits. (Pop, 1,460) The interim manager of this Eastern Shore town may be a candidate for the permanent position, for which an executive search firm will be used. Reqs. a bachelor's degree (master's preferred) and 2-5 yrs. exper. in local govt. administration. Must demonstrate knowledge, skills and abilities in finance, public utilities, planning and zoning, as well as project management."
So I'm doing continuing education through our state ICMA chapter, taking advantage of volunteer project management and leadership with the local arts council, and looking into mentorship through ICMA programs (http://icma.org/en/university/leadership_development). I think the best opportunities are in management fellowships where localities of varying size explicitly cultivate new managers.
Are similar opportunities available in your area? I'm curious how regions vary in this.