Fear not, government has ever had a shortage of people. What you aren't considering is the non-college grad community. We in the DoD will be losing tens of thousands of high quality junior and mid grade personnel who will fill in the gaps nicely. How many of those choose government service in unknown, but given the civilian market, my guess is quite a few. I am also encouraged by the percentage of graduates going on to graduate schools. Those are potential recruits down the line. As a large employer of graduate students, we should be sponsoring scholarships for such folks and encourage that.
For me recruitment isn't the problem, its retention. With the reductions, freezes, re-evaluation of retirement and health care benefits, those more than anything will have an impact on both recruitment and retention. We should tread lightly here and ensure we balance the right insentives with the need for talent.