I am German but am getting a US JD (no European law degree). I am debating applying to the College for a postgraduate degree in law. What are the job prospects coming out of the College? I would be mainly interested in law firms in Brussels or London. Thanks.

why would a german want to work in brussels if one can make much more money in germany for the same job???

Because I have no German law degree, and you basically can't get a job in a law firm in Germany without being qualified there).