let me say only this: legal history that makes no argument is not good legal history. Legal history that is principally "prospective" is sometimes fine but can often be, well, "law office history," history in the service of advocacy. This sort of history may work in an amicus brief, but would not make it through peer review in a history journal.
Legal history has its place, but you will be fighting a very large uphill battle in submitting a piece that has few to none prospective and/or normative conclusions.
What will Mary Dudziak say?
There is a diversity of methodologies in legal history, but legal history helps us understand the nature of legal system, and the relationship between law and social change. New transnational and comparative work (e.g. here and here), to take just one example, helps us to see that the new interest in globalization is not so new, and provides a window on the way national legal ideas have transnational sources and impacts. The sort of arguments found in historical work will generally take a different form than arguments in legal theory. We have a division of labor in the academy.
At a time when history has become a form of analysis on the Supreme Court (e.g. in PICS, Lopez and many other cases), this is hardly a time to turn away from legal history, including in legal education, in spite of recent contrary comments.
But the dismissal of legal history by law review editors is one reason that publishing in peer reviewed history journals and books, where the critical comments in the editorial process go to the substance of the historical arguments & evidence, can be so much more satisfying. There are, of course, exceptions. It usually depends on whether someone on a particular law review board has an interest and/or expertise in history.
While Lawrence Solum is right to imply that the above quote can be thought of as a parody of law review thinking (there is a more earnest take on the blog in question here), there is a substance behind the parody that needs to be engaged.