The publication process takes a long time—sometimes a year or more—so it's important to search for articles on your topic that have already been written but not yet published. SSRN and bepress are the best sources for unpublished articles and working papers:
Check the Legal Scholarship Blog for conferences, workshops, and calls for papers on your topic. You may find that a law journal is hosting an entire symposium on your topic, or a law professor is currently researching your topic. This will alert you to potential preemption issues that may crop up down the road.
Search for law blog posts on your topic. While a blog post cannot preempt a scholarly article or paper on the same topic, it can help you identify scholars who are interested in your topic. You can then review their published and unpublished works, and set alerts to receive notification of their future publications.